N-CSRS 1 tm2413370d3_ncsrs.htm N-CSRS

 

 

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

 

FORM N-CSR

 

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

 

Investment Company Act file number: 811-04917

 

Morgan Stanley Mortgage Securities Trust
(Exact name of registrant as specified in charter)

 

1585 Broadway, New York, New York   10036
(Address of principal executive offices)   (Zip code)

 

John H. Gernon
1585 Broadway, New York, New York 10036
(Name and address of agent for service)

 

Registrant's telephone number, including area code: 212-762-1886

 

Date of fiscal year end: October 31,

 

Date of reporting period: April 30, 2024

 

 

 

 

 

Item 1 - Report to Shareholders

 

 

 

Morgan Stanley
Mortgage Securities Trust

Semi-Annual Report

April 30, 2024


Morgan Stanley Mortgage Securities Trust

Table of Contents (unaudited)

Welcome Shareholder

   

3

   

Fund Report

   

4

   

Performance Summary

   

8

   
Expense Example    

9

   

Portfolio of Investments

   

11

   

Statement of Assets and Liabilities

   

28

   
Statement of Operations    

29

   

Statements of Changes in Net Assets

   

30

   

Notes to Financial Statements

   

31

   
Financial Highlights    

49

   

Liquidity Risk Management Program

   

54

   

Important Notices

   

55

   

U.S. Customer Privacy Notice

   

57

   


2


Welcome Shareholder,

We are pleased to provide this semi-annual report, in which you will learn how your investment in Morgan Stanley Mortgage Securities Trust (the "Fund") performed during the latest six-month period. It includes an overview of the market conditions and discusses some of the factors that affected performance during the reporting period. In addition, the report contains financial statements and a list of portfolio holdings.

Morgan Stanley Investment Management is a client-centric, investor-led organization. Our global presence, intellectual capital, and breadth of products and services enable us to partner with investors to meet the evolving challenges of today's financial markets. We aim to deliver superior investment service and to empower our clients to make the informed decisions that help them reach their investment goals.

As always, we thank you for selecting Morgan Stanley Investment Management and look forward to working with you in the months and years ahead.

This material must be preceded or accompanied by a prospectus for the fund being offered.

Market forecasts provided in this report may not necessarily come to pass. There is no assurance that the Fund will achieve its investment objective. The Fund is subject to market risk, which is the possibility that market values of securities owned by the Fund will decline and, therefore, the value of the Fund's shares may be less than what you paid for them. Accordingly, you can lose money investing in this Fund. Please see the prospectus for more complete information on investment risks.


3


Fund Report (unaudited)

For the six months ended April 30, 2024

Total Return for the 6 Months Ended April 30, 2024

 
Class A  

Class L

 

Class I

 

Class C

 

Class R6

 
Bloomberg
U.S.
Universal
Index1(i)
  Bloomberg
U.S.
Mortgage
Backed
Securities
(MBS)  
Index2
 
  5.54

%

   

5.30

%

   

5.65

%

   

5.18

%

   

5.55

%

   

5.44

%

   

5.32

%

 

The performance of Morgan Stanley Mortgage Securities Trust's (the "Fund") five share classes varies because each has different expenses. The Fund's total returns assume the reinvestment of all distributions but do not reflect the deduction of any applicable sales charges. Such costs would lower performance. See Performance Summary for standardized performance and benchmark information.

Market Conditions

Tighter spreads, falling interest rates and a flattening yield curve were the dominant themes of the reporting period. Securitized credit spreads tightened materially, most notably during the first four months of 2024, and U.S. agency mortgage-backed securities (MBS) spreads tightened 25 basis points (bps) over the six-month period.(ii)

For the six-month period as a whole, fixed income markets performed well, in the portfolio management team's view, as interest rates rallied sharply and credit spreads tightened. Securitized credit market spreads tightened during the period, albeit to a lesser degree than other fixed income sectors, as corporate spreads began tightening in 2023 but securitized spreads did not begin to tighten until 2024. Additionally, securitized credit did not benefit as much from the sharp drop in interest rates given their shorter duration nature. However, securitized credit performed in line with other sectors due to the high income earnings of the securities.

Overall demand levels remained strong during the period, but the portfolio management team believes it will be challenging to push spreads much tighter from these levels. Securitized credit sectors were among the best performing sectors in the first four months of 2024.

As of the end of the reporting period, the portfolio management team also believed that rates were likely to remain in a range for much of 2024, and that returns result primarily from income earnings in the coming months. The portfolio management team believed that

(i)  "Bloomberg®​" and the Bloomberg Index/Indices used are service marks of Bloomberg Finance L.P. and its affiliates, and have been licensed for use for certain purposes by Morgan Stanley Investment Management (MSIM). Bloomberg is not affiliated with MSIM, does not approve, endorse, review, or recommend any product, and does not guarantee the timeliness, accurateness, or completeness of any data or information relating to any product.

(ii)  Source: Bloomberg L.P. Data as of April 30, 2024. One basis point = 0.01%


4


rate levels during the period contributed to stress for many borrowers, which they believe may have contributed to stress for some consumer asset-backed securities (ABS), particularly those involving lower income borrowers. Commercial real estate also was challenged by financing rates during the period, and some sectors declines in operating revenue in 2024.

Residential mortgage credit opportunities remained the portfolio management team's favorite sector as of the end of the reporting period, and it was the one sector where they remained comfortable going down the credit spectrum, compared to a more cautious approach to lower rated ABS and commercial mortgage-backed securities (CMBS). The portfolio management team moved from a neutral to a positive view on agency MBS valuations as of the end of the reporting period, given that it was one of the very few sectors that have cheapened in 2024 year-to-date. Agency MBS continued to remain attractive versus investment grade corporate spreads and versus historical agency MBS spreads, but the portfolio management team believed that agency MBS spreads had stabilized.

Overall, the portfolio management team continued to believe the securitized market offered a unique opportunity to seek yields in line with high yield indexes, yet with an average credit rating of A+. The portfolio management team continued to believe that fundamental credit conditions remained stable, especially for residential mortgage-backed securities (RMBS), which comprised the majority of the portfolio. The portfolio management team also believed there were opportunities in the commercial real estate and ABS sectors, but more caution was exercised in these markets.

Performance Analysis

The Fund's Class A, I and R6 shares outperformed the Bloomberg U.S. Universal Index and the Bloomberg U.S. Mortgage Backed Securities (MBS) Index (the "Index"), and Class L and C shares underperformed both indexes for the six months ended April 30, 2024, assuming no deduction of applicable sales charges.

Relative to the Index and to most other fixed income sectors, the Fund performed well during the six-month period. Although spreads tightened more materially across other fixed income sectors and other longer duration sectors benefited more from the rally in interest rates, the Fund's performance kept pace with or outperformed most other fixed income sectors for the six-month period overall due to high income earnings of the Fund's holdings. The Fund's largest contributor to outperformance was its allocation to U.S. RMBS, which benefited from strong cash flow carry, spread tightening, and the drop in interest rates, given that many of these securities are fixed-rate in nature. U.S. residential-related CMBS and U.S. residential ABS also performed well due to tighter spreads and strong income earnings. Aircraft ABS also contributed to the Fund's performance relative to the Index as global flight traffic recovered to pre-pandemic levels after several years of lower volumes. European securitized holdings underperformed comparable U.S. markets due to their floating-rate nature, as interest rates declined during the period. On a relative basis, the Fund's shorter duration positioning detracted from performance versus the Index, as interest rates fell sharply during the period.

The Fund's allocation to U.S. agency MBS also contributed materially to performance on an absolute


5


basis as spreads tightened and, given their longer duration nature, they benefited materially from the decline in interest rates. However, on a relative basis the Fund's agency MBS allocation slightly underperformed the Index during the period, as an overweight to higher-coupon MBS underperformed lower-coupon MBS as interest rates came down. On an absolute basis, all sectors had positive returns as interest rates fell and spreads tightened across all markets.

There is no guarantee that any sectors mentioned will continue to perform as discussed herein or that securities in such sectors will be held by the Fund in the future.

PORTFOLIO COMPOSITION* as of 04/30/24

 

Mortgages — Other

   

34.6

%

 

Agency Fixed Rate Mortgages

   

25.4

   

Asset-Backed Securities

   

16.3

   

Short-Term Investments

   

15.2

   

Commercial Mortgage-Backed Securities

   

4.5

   
Collateralized Mortgage Obligations — Agency
Collateral Series
   

3.8

   

Agency Adjustable Rate Mortgage

   

0.2

   

Corporate Bond

   

0.0

**

 

*  Does not include open futures contracts with a value of $168,098,524 and total unrealized depreciation of $2,652,847. Does not include open foreign currency forward exchange contracts with net unrealized appreciation of $30,319.

**  Amount is less than 0.05%.

LONG-TERM CREDIT ANALYSIS as of 04/30/24

 

AAA

   

56.4

%

 

AA

   

2.3

   

A

   

5.6

   

BBB

   

1.9

   

BB

   

4.0

   

B or Below

   

4.0

   

Not Rated

   

25.8

   

Subject to change daily. Provided for informational purposes only and should not be deemed as a recommendation to buy or sell the types of securities mentioned above. All percentages for portfolio composition data are stated as a percentage of total investments and all percentages for long-term credit analysis data are stated as a percentage of total long-term investments.

Security ratings disclosed with the exception for those labeled "not rated" is an aggregation of the highest security level rating amongst Standard & Poor's Ratings Group ("S&P"), Moody's Investors Services, Inc. ("Moody's") and Fitch Ratings ("Fitch"), each a Nationally Recognized Statistical Ratings Organization ("NRSRO").

Morgan Stanley is a full-service securities firm engaged in securities trading and brokerage activities, investment banking, research and analysis, financing and financial advisory services.


6


Investment Strategy

The Fund normally invests at least 80% of its assets in mortgage-related securities. This policy may be changed without shareholder approval; however, you would be notified upon 60 days' notice in writing of any changes. These mortgage-related securities may include mortgage-backed securities such as mortgage pass-through securities, collateralized mortgage obligations ("CMOs"), stripped mortgage-backed securities ("SMBS"), commercial mortgage-backed securities ("CMBS") and inverse floating rate obligations ("inverse floaters"). The mortgage-backed securities in which the Fund invests may be issued or guaranteed by the U.S. Government, its agencies or instrumentalities or may be offered by non-governmental issuers, such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers. The Fund is not limited as to the maturities (when a debt security provides its final payment) or types of mortgage-backed securities in which it may invest.


7


Performance Summary (unaudited)

Average Annual Total Returns—Period Ended April 30, 2024

 

Symbol

  Class A Shares*
(since 07/28/97)
MTGAX
  Class L Shares**
(since 07/28/97)
MTGCX
  Class I Shares
(since 07/28/97)
MTGDX
  Class C Shares††
(since 04/30/15)
MSMTX
  Class R6 Shares†††
(since 06/15/18)
MORGX
 
1 Year
 
  2.12
–1.214

%3

  1.76

%3

  2.39

%3

  1.35
0.384

%3

  2.41

%3

 
5 Years
 
  0.983
​0.314
  0.703
​—
  1.373
​—
  0.233
​0.234
  1.383
​—
 
10 Years
 
  2.553
​2.224
  2.283
​—
  2.953
​—
 
 
 
Since
Inception
  3.903
​3.774
  3.373
​—
  4.123
​—
  1.613
​1.614
  1.943
​—
 
Gross
Expense Ratio
   

1.20

     

2.22

     

0.91

     

2.01

     

26.50

   

          

Performance data quoted represents past performance, which is no guarantee of future results and current performance may be lower or higher than the figures shown. For most recent month-end performance figures, please visit www.morganstanley.com/im/shareholderreports or speak with your Financial Advisor. Investment returns and principal value will fluctuate and fund shares, when redeemed, may be worth more or less than their original cost. The table does not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. Performance for Class A, Class L, Class I, Class C and Class R6 shares will vary due to differences in sales charges and expenses. See the Fund's current prospectus for complete details on fees and sales charges. Expense ratios are as of the Fund's fiscal year-end as outlined in the Fund's current prospectus. Fund's total returns are calculated based on the net asset value as of the last business day of the period.

*  The maximum front-end sales charge for Class A is 3.25%.

**  Class L has no sales charge. Class L shares are closed to new investments.

†  Class I has no sales charge.

††  The maximum contingent deferred sales charge for Class C is 1.0% for shares redeemed within one year of purchase. Class C shares will generally automatically convert to Class A shares eight years after the end of the calendar month in which the shares were purchased. Performance for periods greater than eight years reflects this conversion.

†††  Class R6 has no sales charge.

(1)  The Bloomberg U.S. Universal Index represents the union of the U.S. Aggregate Index, U.S. Corporate High Yield Index, Investment Grade 144A Index, Eurodollar Index, U.S. Emerging Markets Index, and the non-Employee Retirement Income Security Act of 1974 (non-ERISA) eligible portion of the CMBS Index. The index covers U.S. dollar-denominated, taxable bonds that are rated either investment grade or high-yield. The Index is unmanaged and its returns do not include any sales charges or fees. Such costs would lower performance. It is not possible to invest directly in an index. Effective May 1, 2024, the Fund's primary benchmark index was changed from the Bloomberg U.S. Mortgage Backed Securities (MBS) Index to the Bloomberg U.S. Universal Index to comply with the regulation that requires the Fund's primary benchmark to represent the overall applicable market.

(2)  The Bloomberg U.S. Mortgage Backed Securities (MBS) Index tracks agency mortgage backed pass-through securities (both fixed-rate and hybrid ARM) guaranteed by Ginnie Mae (GNMA), Fannie Mae (FNMA) and Freddie Mac (FHLMC). This Index is the Mortgage Backed Securities Fixed Rate component of the Bloomberg U.S. Aggregate Index. The Index is unmanaged and its returns do not include any sales charges or fees. Such costs would lower performance. It is not possible to invest directly in an index.

(3)  Figure shown assumes reinvestment of all distributions and does not reflect the deduction of any sales charges.

(4)  Figure shown assumes reinvestment of all distributions and the deduction of the maximum applicable sales charge. See the Fund's current prospectus for complete details on fees and sales charges.


8


Expense Example (unaudited)

As a shareholder of the Fund, you incur two types of costs: (1) transaction costs, including sales charges (loads) on purchase payments; and (2) ongoing costs, which may include advisory fees, administration fees, distribution and shareholder services (12b-1) fees, and other Fund expenses. This example is intended to help you understand your ongoing costs (in dollars) of investing in the Fund and to compare these costs with the ongoing costs of investing in other mutual funds.

This example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period 11/01/23 – 04/30/24.

Actual Expenses

The first line of the table on the following page provides information about actual account values and actual expenses. You may use the information in this line, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the result by the number in the first line under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes

The second line of the table on the following page provides information about hypothetical expenses based on the Fund's actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund's actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing cost of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transactional costs, such as sales charges (loads). Therefore, the second line of the table is useful in comparing ongoing costs, and will not help you determine the relative total cost of owning different funds. In addition, if these transactional costs were included, your costs would have been higher.


9


Expense Example (unaudited) continued

    Beginning
Account Value
  Ending
Account Value
  Expenses Paid
During Period(1)
 
   

11/01/23

 

04/30/24

  11/01/23 –
04/30/24
 

Class A

 

Actual (5.54% return)

 

$

1,000.00

   

$

1,055.40

   

$

4.50

   

Hypothetical (5% annual return before expenses)

 

$

1,000.00

   

$

1,020.49

   

$

4.42

   

Class L

 

Actual (5.30% return)

 

$

1,000.00

   

$

1,053.00

   

$

5.97

   

Hypothetical (5% annual return before expenses)

 

$

1,000.00

   

$

1,019.05

   

$

5.87

   

Class I

 

Actual (5.65% return)

 

$

1,000.00

   

$

1,056.50

   

$

2.97

   

Hypothetical (5% annual return before expenses)

 

$

1,000.00

   

$

1,021.98

   

$

2.92

   

Class C

 

Actual (5.18% return)

 

$

1,000.00

   

$

1,051.80

   

$

8.52

   

Hypothetical (5% annual return before expenses)

 

$

1,000.00

   

$

1,016.56

   

$

8.37

   

Class R6

 

Actual (5.55% return)

 

$

1,000.00

   

$

1,055.50

   

$

2.71

   

Hypothetical (5% annual return before expenses)

 

$

1,000.00

   

$

1,022.23

   

$

2.66

   

  (1)  Expenses are equal to the Fund's annualized expense ratios of 0.88%, 1.17%, 0.58%, 1.67% and 0.53% for Class A, Class L, Class I, Class C and Class R6 shares, respectively, multiplied by the average account value over the period and multiplied by 182/366 (to reflect the one-half year period).

    Refer to Note 4 in the Notes to Financial Statements for discussion of prior period transfer agency and sub transfer agency fees and expenses that were reimbursed in the current period.


10


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited)

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 
   

Agency Adjustable Rate Mortgage (0.3%)

 

$

873

    Government National Mortgage Association,
Various Pools: (Cost $744,567)
   

3.047

(b)%

 

03/20/71

 

$

764,579

   
   

Agency Fixed Rate Mortgages (30.1%)

 
    Federal Home Loan Mortgage Corporation,
Conventional Pools:
 
 

477

   

  

   

2.00

   

04/01/51

   

350,034

   
 

1,640

   

  

   

2.50

   

05/01/50 - 11/01/52

   

1,262,089

   
 

4,920

   

  

   

3.00

   

04/01/50 - 12/01/51

   

4,000,480

   
 

59

   

  

   

3.50

   

08/01/49

   

50,873

   
 

1,479

   

  

   

4.00

   

07/01/49 - 11/01/52

   

1,299,681

   
 

1,569

   

  

   

4.50

   

10/01/52

   

1,434,432

   
   

Gold Pools:

 
 

562

   

  

   

3.50

   

06/01/42 - 09/01/47

   

504,478

   
 

260

   

  

   

4.00

   

12/01/41 - 10/01/44

   

239,533

   
 

271

   

  

   

4.50

   

03/01/41 - 01/01/49

   

257,901

   
 

54

   

  

   

5.00

   

12/01/40 - 05/01/41

   

54,030

   
 

6

   

  

   

5.50

   

07/01/37

   

5,987

   
 

9

   

  

   

6.00

   

12/01/37

   

9,115

   
 

4

   

  

   

6.50

   

06/01/29

   

4,421

   
 

18

   

  

   

7.50

   

05/01/35

   

18,504

   
 

8

   

  

   

8.00

   

08/01/32

   

8,006

   
 

14

   

  

   

8.50

   

08/01/31

   

14,831

   
    Federal National Mortgage Association,
Conventional Pools:
 
 

1,274

   

  

   

1.50

   

01/01/51 - 03/01/51

   

936,513

   
 

3,845

   

  

   

2.00

   

11/01/50 - 11/01/51

   

2,816,253

   
 

4,614

   

  

   

2.50

   

02/01/50 - 02/01/52

   

3,534,636

   
 

2,645

   

  

   

3.00

   

08/01/46 - 04/01/52

   

2,163,100

   
 

4,858

   

  

   

3.50

   

09/01/42 - 10/01/52

   

4,144,418

   
 

820

   

  

   

4.00

   

04/01/45 - 01/01/49

   

746,876

   
 

411

   

  

   

4.50

   

08/01/40 - 08/01/49

   

380,797

   
 

69

   

  

   

5.00

   

12/01/40 - 07/01/41

   

67,864

   
 

5

   

  

   

5.50

   

08/01/37

   

4,583

   
 

141

   

  

   

6.50

   

02/01/28 - 11/01/33

   

143,791

   
 

10

   

  

   

7.00

   

10/01/30 - 06/01/32

   

9,607

   
 

22

   

  

   

7.50

   

08/01/37

   

22,629

   
 

21

   

  

   

8.00

   

04/01/33

   

21,650

   

See Notes to Financial Statements
11


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 

$

23

   

  

   

8.50

%

 

10/01/32

 

$

24,404

   
 

2

   

  

   

9.50

   

04/01/30

   

2,520

   
   

May TBA

     
 

4,000

   

(a)

   

2.50

   

05/01/54

   

3,167,344

   
 

12,000

   

(a)

   

3.00

   

02/01/52

   

9,917,344

   
 

10,000

   

(a)

   

4.00

   

06/01/52

   

8,942,187

   
 

4,000

   

(a)

   

4.50

   

05/01/54

   

3,688,125

   
 

10,000

   

(a)

   

5.00

   

05/01/54

   

9,482,421

   
 

5,000

   

(a)

   

5.50

   

05/01/54

   

4,856,445

   
 

8,000

   

(a)

   

6.00

   

05/01/54

   

7,931,563

   
 

2,000

   

(a)

   

6.50

   

05/01/54

   

2,016,328

   
    Government National Mortgage Association,
June TBA
     
 

4,500

   

(a)

   

6.00

   

06/20/54

   

4,491,596

   
 

2,000

   

(a)

   

6.50

   

06/20/54

   

2,020,059

   
   

May TBA

     
 

1,000

   

(a)

   

4.00

   

05/20/54

   

906,556

   
   

Various Pools:

     
 

2,510

   

  

   

2.50

   

03/20/50 - 04/20/51

   

2,027,685

   
 

1,101

   

  

   

3.00

   

09/20/49 - 08/20/50

   

915,608

   
 

1,780

   

  

   

3.50

   

05/20/43 - 10/20/50

   

1,547,532

   
 

2,044

   

  

   

4.00

   

07/15/44 - 11/20/53

   

1,819,707

   
 

279

   

  

   

4.50

   

12/20/48 - 12/20/49

   

259,104

   
 

294

   

  

   

5.00

   

05/20/41 - 06/20/49

   

282,623

   
 

391

   

  

   

6.00

   

08/20/52

   

391,847

   
 

1,090

   

  

   

6.50

   

11/20/52

   

1,104,597

   
 

4,700

   

  

   

7.00

   

11/20/50 - 06/20/53

   

4,765,479

   
 

3,385

   

  

   

7.50

   

12/20/48 - 10/20/53

   

3,411,098

   
 

1,794

   

  

   

8.50

   

12/20/49

   

1,813,801

   
        Total Agency Fixed Rate Mortgages (Cost $104,551,711)            

100,293,085

   
   

Asset-Backed Securities (19.3%)

     
 

304

    ABFC 2004-OPT2 Trust
1 Month Term SOFR + 0.89%
   

6.211

(b)

 

10/25/33

   

295,907

   
 

277

    ABFC 2004-OPT4 Trust, Class M1
1 Month Term SOFR + 1.01%
   

6.331

(b)

 

02/25/34

   

274,737

   
 

109

    ABFC 2005-WF1 Trust
1 Month Term SOFR + 1.06%
   

6.376

(b)

 

07/25/34

   

104,879

   

See Notes to Financial Statements
12


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 
   

Amortizing Residential Collateral Trust

     

$

542

   

1 Month Term SOFR + 0.40%

   

6.084

(b)%

 

10/25/31

 

$

523,136

   
 

293

   

1 Month Term SOFR + 0.87%

   

6.191

(b)

 

10/25/32

   

265,769

   
 

783

    Argent Securities, Inc. Asset-Backed Pass-Through
Certificates
5.74% - 1 Month Term SOFR
   

3.689

(c)

 

12/25/33

   

891,243

   
 

24,032

   

B2R Mortgage Trust, Class XB, IO (d)

   

1.12

(b)

 

05/15/48

   

52,484

   
 

1,119

    Bayview Financial Revolving Asset Trust, Class A1
1 Month Term SOFR + 1.11% (d)
   

6.433

(b)

 

12/28/40

   

1,110,731

   
 

306

    Bear Stearns Asset-Backed Securities I Trust, Class M8
1 Month Term SOFR + 5.36%
   

10.681

(b)

 

10/25/34

   

304,346

   
 

64

    Bear Stearns Asset-Backed Securities Trust
1 Month Term SOFR + 1.41%
   

6.731

(b)

 

10/27/32

   

63,551

   
 

1,500

   

Bridge Trust, Class E2 (d)

   

6.30

   

11/17/37

   

1,421,597

   
 

207

    Business Loan Express Business Loan Trust
1 Month Term SOFR + 0.51% (d)
   

5.83

(b)

 

10/20/40

   

188,312

   
 

1,920

   

Cascade MH Asset Trust (d)

   

4.25

   

08/25/54

   

1,729,576

   
   

Conn's Receivables Funding LLC

     
 

900

   

(d)

   

0.00

   

12/15/26

   

832,047

   
 

465

   

(d)

   

9.52

   

12/15/26

   

465,955

   
 

2,500

   

(d)

   

9.80

   

01/16/29

   

2,531,936

   
 

2,000

   

(d)

   

10.00

   

01/17/28

   

2,018,748

   
   

Conseco Finance Corp., Class M1

     
 

1,173

   

  

   

7.03

(b)

 

07/15/28

   

1,126,403

   
 

1,246

   

  

   

7.75

(b)

 

06/15/27

   

1,243,557

   
 

14

   

Conseco Finance Securitizations Corp.

   

7.424

(b)

 

03/01/33

   

14,011

   
 

2,945

    CoreVest American Finance 2020-4 Trust
IO (d)
   

4.012

(b)

 

12/15/52

   

149,719

   
 

3,324

   

CoreVest American Finance Ltd., Class XA, IO (d)

   

3.145

(b)

 

07/15/54

   

145,616

   
 

649

    Countrywide Asset-Backed Certificates, Class M2
1 Month Term SOFR + 2.29% (d)
   

7.606

(b)

 

03/25/33

   

635,359

   
 

575

    Delta Funding Home Equity Loan Trust, Class A1A
1 Month Term SOFR + 0.93%
   

6.256

(b)

 

09/15/29

   

551,657

   
   

ECAF I Ltd.

     
 

33

   

(Ireland) (d)

   

3.473

   

06/15/40

   

18,693

   
 

566

   

(d)

   

4.947

   

06/15/40

   

396,055

   
 

110

    EquiFirst Mortgage Loan Trust
1 Month Term SOFR + 3.11%
   

8.431

(b)

 

10/25/34

   

105,587

   

EUR

1,006

    European Residential Loan Securitisation 2019-NPL1 DAC
1 Month EURIBOR + 3.25% (Ireland)
   

7.069

(b)

 

07/24/54

   

1,068,490

   

See Notes to Financial Statements
13


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 

EUR

525

    European Residential Loan Securitisation 2019-NPL2 DAC
1 Month EURIBOR + 3.00% (Ireland)
   

6.819

(b)%

 

02/24/58

 

$

560,923

   
   

Finance of America HECM Buyout

     

$

4,000

   

  

   

6.00

(b)

 

08/01/32

   

2,854,265

   
 

1,000

   

(d)

   

6.414

(b)

 

02/25/32

   

889,402

   
 

2,000

   

(d)

   

7.87

(b)

 

02/25/32

   

1,743,582

   
 

149

    Financial Asset Securities Corp. AAA Trust
1 Month Term SOFR + 0.52% (d)
   

5.843

(b)

 

02/27/35

   

142,792

   
   

FMC GMSR Issuer Trust

     
 

1,200

   

(d)

   

3.62

(b)

 

07/25/26

   

1,053,733

   
 

1,000

   

(d)

   

4.36

(b)

 

07/25/26

   

847,860

   
 

1,000

   

(d)

   

4.45

(b)

 

01/25/26

   

916,955

   
 

1,000

   

(d)

   

10.07

   

07/25/27

   

988,464

   
 

920

   

FortiFi, Class A (d)

   

6.23

   

09/20/59

   

856,039

   
 

222

   

GAIA Aviation Ltd. (Cayman Islands) (d)

   

3.967

   

12/15/44

   

207,670

   
 

2,042

    Harvest SBA Loan Trust, Class A
SOFR30A + 3.25% (d)
   

8.694

(b)

 

10/25/50

   

2,049,224

   
 

1,087

   

Home Partners of America 2019-1 Trust (d)

   

3.866

   

10/19/39

   

946,433

   
 

950

   

JOL Air Ltd., Class A (Cayman Islands) (d)

   

3.967

   

04/15/44

   

884,924

   
 

236

   

Kestrel Aircraft Funding Ltd., Class A (d)

   

4.25

   

12/15/38

   

219,644

   
   

Lehman ABS Manufactured Housing Contract Trust

     
 

1,468

   

  

   

0.00

   

06/15/33

   

1,366,335

   
 

122

   

  

   

6.63

(b)

 

04/15/40

   

122,630

   
 

1,500

    Loandepot GMSR Master Trust, Class A
1 Month Term SOFR + 3.66% (d)
   

8.984

(b)

 

10/16/25

   

1,458,303

   
 

764

   

LoanMe Trust Prime (d)

   

5.00

   

09/15/34

   

726,007

   

EUR

3,254

    LSF11 Boson Investments SARL Compartment 2,
Class A1,
3 Month EURIBOR + 2.00% (Spain)
   

5.945

(b)

 

11/25/60

   

3,291,876

   

$

1,025

    MASTR Asset Securitization Trust, Class M3
1 Month Term SOFR + 3.26%
   

8.581

(b)

 

10/25/32

   

949,035

   
 

97

   

MERIT Securities Corp.

   

7.88

   

12/28/33

   

97,058

   
 

83

    Merrill Lynch Mortgage Investors Trust, Class B1
1 Month Term SOFR + 2.81%
   

8.131

(b)

 

01/25/35

   

79,344

   
 

255

   

METAL LLC (d)

   

4.581

   

10/15/42

   

165,646

   
 

327

    New Century Home Equity Loan Trust
1 Month Term SOFR + 0.91%
   

3.963

(b)

 

11/25/33

   

267,524

   
 

1,709

   

New Residential Mortgage LLC, Class A,

   

5.437

   

06/25/25 - 07/25/25

   

1,677,929

   

GBP

1,000

    Newday Funding Master Issuer PLC
3 Month GBP SONIA + 5.00% (United Kingdom) (d)
   

10.209

(b)

 

07/15/30

   

1,280,142

   

See Notes to Financial Statements
14


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 
   

Newtek Small Business Loan Trust

 

$

1,023

   

Daily U.S. Prime Rate - 0.70% (d)

   

7.80

(b)%

 

10/25/49

 

$

1,019,566

   
 

90

   

Daily U.S. Prime Rate - 0.55% (d)

   

7.95

(b)

 

02/25/44

   

89,688

   
 

849

   

Daily U.S. Prime Rate - 0.50% (d)

   

8.00

(b)

 

07/25/50

   

847,604

   
   

NRZ Excess Spread-Collateralized Notes

 
 

410

   

(d)

   

2.981

   

03/25/26

   

384,872

   
 

330

   

(d)

   

3.844

   

12/25/25

   

317,086

   
 

597

   

NRZ FHT Excess LLC, Class A (d)

   

4.212

   

11/25/25

   

574,382

   
   

Oakwood Mortgage Investors, Inc.

 
 

849

   

  

   

7.405

(b)

 

06/15/31

   

91,474

   
 

35

   

  

   

7.72

   

04/15/30

   

34,356

   
 

82

   

  

   

7.84

(b)

 

11/15/29

   

81,679

   

EUR

771

    Palatino SPV, Class AR
6 Month EURIBOR + 2.50% (Italy)
   

6.55

(b)

 

12/01/45

   

784,786

   
   

PMT FMSR Issuer Trust

 

$

2,000

   

1 Month Term SOFR + 3.11% (d)

   

8.432

(b)

 

03/25/26

   

2,025,213

   
 

2,200

   

SOFR30A + 4.19% (d)

   

9.52

(b)

 

06/25/27

   

2,229,656

   
   

PNMAC GMSR Issuer Trust

 
 

2,700

   

1 Month Term SOFR + 3.20% (d)

   

8.517

(b)

 

03/25/29

   

2,731,851

   
 

1,500

   

SOFR30A + 4.25% (d)

   

9.58

(b)

 

05/25/27

   

1,522,972

   

EUR

759

    Prosil Acquisition SA, Class A
3 Month EURIBOR + 2.00% (Spain)
   

5.912

(b)

 

10/31/39

   

673,241

   

$

417

    Quest Trust, Class M2
1 Month Term SOFR + 3.86% (d)
   

9.181

(b)

 

05/25/33

   

429,630

   
 

1,590

   

Raptor Aircraft Finance I LLC (d)

   

4.213

   

08/23/44

   

1,311,005

   
 

312

    ReadyCap Lending Small Business Loan Trust
Daily U.S. Prime Rate - 0.50% (d)
   

8.00

(b)

 

12/27/44

   

311,964

   
 

266

    Saxon Asset Securities Trust
1 Month Term SOFR + 1.24%
   

6.556

(b)

 

12/25/32

   

239,555

   
 

693

   

Shenton Aircraft Investment I Ltd. (d)

   

4.75

   

10/15/42

   

649,096

   
 

214

   

Shenton Aircraft Investment Ltd.

   

5.75

   

10/15/42

   

139,174

   

EUR

1,000

    SLM Student Loan Trust, Class A8
3 Month EURIBOR + 0.55%
   

4.432

(b)

 

01/25/40

   

981,952

   

$

1,000

    STAR 2022-SFR3 Trust, Class D
1 Month Term SOFR + 2.55% (d)
   

7.871

(b)

 

05/17/39

   

986,250

   
 

212

   

Start II Ltd. (Bermuda) (d)

   

4.089

   

03/15/44

   

198,075

   
 

266

    Terwin Mortgage Trust, Class M1
1 Month Term SOFR + 0.94%
   

6.256

(b)

 

03/25/35

   

255,818

   
 

330

   

WAVE Trust (d)

   

3.844

   

11/15/42

   

291,768

   
        Total Asset-Backed Securities (Cost $65,538,862)            

64,376,553

   

See Notes to Financial Statements
15


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 
   

Collateralized Mortgage Obligations - Agency Collateral Series (4.5%)

     
    Federal Home Loan Mortgage Corporation,
IO REMIC
     

$

81

   

  

   

0.00

(b)%

 

10/15/41

 

$

3,210

   
 

135

   

  

   

0.001

(b)

 

10/15/39

   

4,299

   
 

166

   

  

   

0.088

(b)

 

04/15/39

   

6,466

   
 

459

   

  

   

0.11

(b)

 

09/15/41

   

17,324

   
 

524

   

  

   

0.156

(b)

 

10/15/40

   

24,931

   
 

227

   

  

   

0.273

(b)

 

08/15/42

   

8,789

   
 

386

   

5.89% - SOFR30A

   

0.556

(c)

 

11/15/43 - 06/15/44

   

24,956

   
 

24

   

  

   

5.00

   

08/15/41

   

5,305

   
   

IO REMIC PAC

     
 

8,719

   

  

   

2.00

   

10/25/50

   

1,089,599

   
   

IO STRIPS

     
 

37

   

  

   

7.00

   

06/15/30

   

4,524

   
   

REMIC

     
 

56

   

12.00% - 2.67 x 1 Month USD LIBOR

   

0.00

(c)

 

12/15/43

   

47,146

   
 

83

   

  

   

3.50

   

02/15/42

   

73,418

   
    Federal National Mortgage Association,
IO REMIC
     
 

224

   

  

   

0.039

(b)

 

10/25/39

   

11,832

   
 

809

   

  

   

0.078

(b)

 

03/25/46

   

29,792

   
 

79

   

5.54% - SOFR30A

   

0.206

(c)

 

11/25/41

   

711

   
 

149

   

  

   

0.239

(b)

 

03/25/44

   

4,703

   
 

391

   

5.94% - SOFR30A

   

0.606

(c)

 

06/25/42

   

29,619

   
 

42

   

6.44% - SOFR30A

   

1.106

(c)

 

08/25/41

   

609

   
 

540

   

  

   

2.00

   

07/25/50

   

270,371

   
   

IO STRIPS

     
 

7

   

  

   

7.00

   

11/25/27

   

571

   
 

30

   

  

   

8.00

   

05/25/30 - 06/25/30

   

3,523

   
 

1

   

  

   

8.50

   

10/25/24

   

12

   
   

REMIC

     
 

16

   

  

   

0.002

(b)

 

04/25/39

   

13,695

   
 

1,949

   

SOFR30A + 1.00%

   

6.33

(b)

 

03/25/54

   

1,936,120

   
 

1,821

   

  

   

6.50

   

03/25/54

   

1,738,535

   
   

REMIC PAC

     
 

244

   

  

   

5.00

   

07/25/50

   

233,416

   

See Notes to Financial Statements
16


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 
   

Government National Mortgage Association,

 

$

28

   

1 Month Term SOFR + 0.56%

   

5.887

(b)%

 

02/20/61

 

$

28,078

   
 

13

   

1 Month Term SOFR + 0.81%

   

6.137

(b)

 

08/20/63

   

12,819

   
 

1

   

1 Month Term SOFR + 0.88%

   

6.207

(b)

 

02/20/66

   

852

   
   

IO

 
 

130

   

  

   

0.00

(b)

 

12/20/67

   

1,004

   
 

6,108

   

  

   

0.011

(b)

 

12/20/70

   

286,394

   
 

50

   

  

   

0.013

(b)

 

12/20/62

   

85

   
 

44

   

  

   

0.023

(b)

 

01/20/63

   

211

   
 

39

   

  

   

0.044

(b)

 

09/20/62

   

283

   
 

11

   

  

   

0.084

(b)

 

04/20/62

   

216

   
 

43

   

  

   

0.102

(b)

 

08/20/61

   

808

   
 

48

   

  

   

0.216

(b)

 

10/20/62

   

2,120

   
 

21

   

  

   

0.219

(b)

 

10/20/61

   

1,134

   
 

92

   

  

   

0.27

(b)

 

05/20/61

   

4,500

   
 

46

   

  

   

0.302

(b)

 

01/20/62

   

2,746

   
 

8,730

   

  

   

0.334

(b)

 

05/20/72

   

447,624

   
 

9

   

  

   

0.334

(b)

 

04/20/61

   

582

   
 

5,003

   

  

   

0.433

(b)

 

10/20/64

   

317,434

   
 

4,531

   

  

   

0.441

(b)

 

05/20/67

   

176,165

   
 

2,162

   

  

   

0.498

(b)

 

02/20/65

   

68,690

   
 

44

   

  

   

0.506

(b)

 

11/20/61

   

4,359

   
 

228

   

5.89% - 1 Month Term SOFR

   

0.57

(c)

 

08/20/42

   

17,445

   
 

1,430

   

  

   

0.638

(b)

 

08/20/58

   

8,275

   
 

268

   

5.99% - 1 Month Term SOFR

   

0.67

(c)

 

04/20/41 - 08/20/42

   

20,156

   
 

263

   

6.03% - 1 Month Term SOFR

   

0.71

(c)

 

12/20/43

   

23,392

   
 

12,572

   

  

   

0.807

(b)

 

06/20/66

   

383,355

   
 

1,189

   

  

   

0.856

(b)

 

06/20/67

   

66,989

   
 

5,244

   

  

   

0.863

(b)

 

12/20/66

   

246,761

   
 

164

   

6.19% - 1 Month Term SOFR

   

0.87

(c)

 

09/20/43

   

6,044

   
 

16,448

   

  

   

0.961

(b)

 

04/20/66

   

809,700

   
 

126

   

6.44% - 1 Month Term SOFR

   

1.116

(c)

 

08/16/34

   

5,630

   
 

5,714

   

  

   

1.177

(b)

 

03/20/67

   

326,393

   
 

145

   

  

   

1.233

(b)

 

04/20/62

   

5,245

   
 

5,592

   

  

   

1.253

(b)

 

02/20/68

   

217,114

   
 

261

   

  

   

1.279

(b)

 

01/20/68

   

13,342

   
 

426

   

  

   

1.37

(b)

 

03/20/67

   

18,095

   
 

654

   

  

   

1.407

(b)

 

01/20/64

   

17,075

   
 

1,088

   

  

   

1.552

(b)

 

05/20/64

   

40,321

   
 

63

   

  

   

1.577

(b)

 

04/20/60

   

4,980

   

See Notes to Financial Statements
17


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 

$

183

   

  

   

1.621

(b)%

 

04/20/63

 

$

8,164

   
 

9

   

  

   

1.67

(b)

 

02/20/63

   

375

   
 

1,209

   

  

   

1.963

(b)

 

06/20/64

   

60,463

   
 

20

   

  

   

1.986

(b)

 

08/20/63

   

822

   
 

39

   

  

   

2.247

(b)

 

10/20/60

   

4,644

   
 

5

   

  

   

2.411

(b)

 

07/20/63

   

469

   
 

1,845

   

  

   

2.50

   

11/20/51

   

253,050

   
 

33

   

  

   

2.531

(b)

 

02/20/60

   

1,820

   
 

23

   

  

   

2.847

(b)

 

03/20/62

   

1,803

   
 

80

   

  

   

3.103

(b)

 

04/20/62

   

10,224

   
 

26

   

  

   

3.167

(b)

 

02/20/63

   

2,897

   
 

628

   

  

   

3.50

   

10/16/42

   

97,840

   
 

15

   

  

   

3.587

(b)

 

09/20/60

   

2,237

   
 

24

   

  

   

5.00

   

02/16/41

   

4,705

   
   

IO PAC

 
 

66

   

  

   

3.50

   

06/20/41

   

2,615

   
 

25

   

  

   

4.50

   

05/20/40

   

1,491

   
 

13

   

  

   

5.00

   

10/20/40

   

817

   
   

IO REMIC

 
 

2,541

   

  

   

0.035

(b)

 

08/20/69

   

150,314

   
 

394

   

  

   

0.251

(b)

 

10/20/67

   

8,652

   
 

3,098

   

  

   

0.336

(b)

 

11/20/64

   

116,380

   
 

830

   

  

   

0.372

(b)

 

10/20/67

   

46,650

   
 

1,165

   

  

   

0.40

(b)

 

11/20/67

   

74,632

   
 

579

   

  

   

0.434

(b)

 

06/20/67

   

19,772

   
 

2,416

   

  

   

0.486

(b)

 

09/20/64

   

166,408

   
 

1,041

   

  

   

0.84

(b)

 

07/20/67

   

49,645

   
 

4,834

   

  

   

0.863

(b)

 

02/20/68

   

174,071

   
 

975

   

  

   

1.191

(b)

 

02/20/68

   

48,858

   
 

240

   

  

   

1.232

(b)

 

02/20/68

   

11,376

   
 

1,601

   

  

   

1.729

(b)

 

07/20/67

   

46,204

   
 

6,941

   

  

   

2.00

   

11/20/50

   

807,447

   
 

3,851

   

  

   

2.068

(b)

 

01/20/66

   

96,819

   
 

1,568

   

  

   

2.33

(b)

 

07/20/65

   

40,714

   
 

6,789

   

  

   

2.679

(b)

 

06/20/66

   

542,498

   
 

391

   

  

   

3.50

   

05/20/43

   

60,838

   
   

REMIC

 
 

2,964

   

  

   

7.50

   

02/20/54

   

2,961,785

   
        Total Collateralized Mortgage Obligations - Agency Collateral Series (Cost $14,926,929)            

15,047,391

   

See Notes to Financial Statements
18


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 
   

Commercial Mortgage-Backed Securities (5.3%)

     
   

Bayview Commercial Asset Trust,

     

$

1,325

   

1 Month Term SOFR + 0.47% (d)

   

5.791

(b)%

 

07/25/37

 

$

1,238,595

   
 

505

   

1 Month Term SOFR + 0.56% (d)

   

5.881

(b)

 

10/25/36

   

486,365

   
 

573

   

1 Month Term SOFR + 0.65% (d)

   

5.971

(b)

 

10/25/36

   

552,204

   
 

879

   

1 Month Term SOFR + 0.67% (d)

   

5.986

(b)

 

10/25/36

   

842,497

   
 

1,920

   

Citigroup Commercial Mortgage Trust, IO

   

1.019

(b)

 

09/10/58

   

15,400

   
   

Commercial Mortgage Trust,

     
 

806

   

IO

   

0.794

(b)

 

10/10/47

   

531

   
  100    

(d)

   

4.912

(b)

 

07/15/47

   

90,835

   
 

748

   

COOF Securitization Trust, IO (d)

   

2.447

(b)

 

10/25/40

   

42,658

   
 

776

   

COOF Securitization Trust II, IO (d)

   

2.082

(b)

 

08/25/41

   

41,872

   
   

Credit Suisse Mortgage Trust,

     
 

2,000

   

1 Month Term SOFR + 3.14% (d)

   

8.464

(b)

 

09/09/24

   

2,009,941

   
 

878

   

1 Month Term SOFR + 3.57% (d)

   

8.895

(b)

 

05/15/26

   

840,653

   
 

3,000

   

1 Month Term SOFR + 3.83% (d)

   

9.15

(b)

 

08/15/26

   

2,702,640

   
 

1,000

   

DBCG Mortgage Trust (d)

   

8.50

(b)

 

06/15/34

   

1,001,342

   
 

5,248

   

GS Mortgage Securities Corp. Trust, IO (d)

   

0.513

(b)

 

10/10/32

   

17,635

   
   

GS Mortgage Securities Trust,

     
 

500

   

  

   

3.345

   

07/10/48

   

440,888

   
 

1,266

   

IO

   

0.797

(b)

 

09/10/47

   

621

   
 

1,554

   

Harvest Commercial Capital Loan Trust (d)

   

5.964

(b)

 

04/25/52

   

1,371,264

   
 

1,438

    JP Morgan Chase Commercial Mortgage Securities Trust,
IO
   

0.707

(b)

 

12/15/49

   

15,905

   
 

63

   

JPMBB Commercial Mortgage Securities Trust (d)

   

4.776

(b)

 

04/15/47

   

61,558

   
    KGS-Alpha SBA COOF Trust,
IO
         
 

402

   

(d)

   

0.729

(b)

 

08/25/38

   

5,926

   
 

269

   

(d)

   

2.58

(b)

 

04/25/40

   

12,442

   
 

384

   

(d)

   

2.602

(b)

 

07/25/41

   

23,120

   
 

1,000

   

Natixis Commercial Mortgage Securities Trust (d)

   

4.272

(b)

 

05/15/39

   

823,150

   

CAD

8,358

   

Real Estate Asset Liquidity Trust, IO (Canada) (d)

   

1.175

(b)

 

02/12/55

   

237,378

   
 

2,000

   

Retained Vantage Data Centers Issuer LLC (d)

   

5.25

   

09/15/48

   

1,368,420

   

$

599

   

Sutherland Commercial Mortgage Trust (d)

   

2.23

(b)

 

12/25/41

   

511,745

   
 

8,276

   

UBS Commercial Mortgage Trust, IO

   

1.077

(b)

 

03/15/51

   

238,781

   
 

535

   

Velocity Commercial Capital Loan Trust (d)

   

6.90

   

05/25/47

   

533,485

   

See Notes to Financial Statements
19


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 

$

538

    VMC Finance 2021-HT1 LLC,
1 Month Term SOFR + 1.76% (d)
   

7.083

(b)%

 

01/18/37

 

$

532,555

   
 

1,529

   

Waterfall Commercial Mortgage Trust (d)

   

4.104

(b)

 

09/14/22

   

1,513,773

   
        Total Commercial Mortgage-Backed Securities (Cost $17,366,351)            

17,574,179

   
   

Corporate Bond (0.0%)‡

     
   

Finance (0.0%)‡

     
 

350

    DP Facilities Data Center Subordinated Pass-Through
Trust (d) (Cost $278,280)
   

0.00

   

11/10/28

   

89,250

   
   

Mortgages - Other (41.0%)

     
 

634

   

510 Asset Backed 2021-NPL1 Trust (d)

   

2.24

   

06/25/61

   

615,143

   
 

1,949

   

A&D Mortgage Trust, Class A1 (d)

   

7.049

   

11/25/68

   

1,972,269

   
 

70

   

Adjustable Rate Mortgage Trust

   

4.962

(b)

 

04/25/35

   

64,599

   

GBP

252

    Alba 2005-1 PLC
3 Month GBP SONIA + 0.72% (United Kingdom)
   

5.947

(b)

 

11/25/42

   

299,075

   
   

Banc of America Funding Trust

     

$

4

   

  

   

5.25

   

07/25/37

   

4,070

   
 

208

   

  

   

5.50

   

09/25/35

   

192,397

   
 

439

    Bear Stearns Asset-Backed Securities I Trust
25.64% - 3.29 x 1 Month USD LIBOR
   

7.79

(c)

 

03/25/36

   

126,059

   
   

Bear Stearns Asset-Backed Securities Trust

     
 

44

   

  

   

4.941

(b)

 

07/25/36

   

42,866

   
 

1,860

   

1 Month Term SOFR + 3.79%

   

9.106

(b)

 

08/25/43

   

1,944,996

   
 

1,000

    Bellemeade Re Ltd., Class B1,
1 Month Term SOFR + 2.61% (d)
   

7.931

(b)

 

07/25/29

   

1,002,952

   
   

Boston Lending Trust

     
 

1,550

   

(d)

   

2.00

(b)

 

07/25/61

   

1,079,666

   
 

3,796

   

(d)

   

3.25

(b)

 

05/25/62

   

3,119,764

   
   

Brean Asset Backed Securities Trust

     
 

5,209

   

(d)

   

4.00

   

09/25/63

   

4,399,273

   
 

1,900

   

(d)

   

4.50

(b)

 

03/25/78

   

1,745,063

   
   

Cascade Funding Mortgage Trust

     
 

1,582

   

(d)

   

2.00

(b)

 

09/25/50 - 02/25/52

   

1,343,070

   
 

2,850

   

(d)

   

3.25

(b)

 

11/25/35 - 09/25/37

   

2,512,999

   
 

1,196

   

(d)

   

3.71

(b)

 

06/25/69

   

1,130,259

   
 

5,500

   

(d)

   

3.75

(b)

 

04/25/25

   

4,755,174

   
 

950

   

(d)

   

3.849

(b)

 

10/27/31

   

901,606

   
 

11,374

   

(d)

   

4.00

(b)

 

02/25/37 - 06/25/69

   

10,087,043

   
 

5,300

   

(d)

   

4.25

(b)

 

04/25/33

   

4,422,029

   

See Notes to Financial Statements
20


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 

$

1,500

   

(d)

   

5.072

(b)%

 

10/27/31

 

$

1,413,901

   
 

88

   

Cendant Mortgage Corp. (d)

   

6.00

(b)

 

07/25/43

   

82,483

   
   

CHL Mortgage Pass-Through Trust

 
 

183

   

  

   

5.50

   

10/25/34

   

174,887

   
 

84

   

  

   

5.531

(b)

 

05/20/34

   

75,659

   
 

143

   

  

   

5.84

(b)

 

10/25/33

   

136,911

   
 

61

   

  

   

6.00

   

12/25/36

   

35,236

   
 

89

    Citigroup Mortgage Loan Trust, Inc.
1 Year CMT + 2.40%
   

7.86

(b)

 

11/25/35

   

88,241

   
   

Countrywide Alternative Loan Trust

 
 

31

   

  

   

5.50

   

02/25/25 - 01/25/36

   

17,659

   
 

110

   

  

   

5.75

   

03/25/34

   

105,233

   
 

71

   

40.02% - 6 x 1 Month USD LIBOR

   

7.432

(c)

 

05/25/37

   

46,580

   
 

75

   

Countrywide Reperforming Loan REMIC Trust (d)

   

8.50

   

06/25/35

   

73,250

   
   

Credit Suisse First Boston Mortgage Securities Corp.

 
 

1,020

   

(d)

   

5.15

   

12/29/31

   

776,290

   
 

321

   

1 Month Term SOFR + 3.41%

   

8.731

(b)

 

02/25/32

   

352,593

   
 

1,272

   

Credit Suisse Mortgage Trust, Class A1 (d)

   

3.904

(b)

 

04/25/62

   

1,176,710

   
   

CSFB Mortgage-Backed Pass-Through Certificates

 
 

211

   

  

   

4.858

(b)

 

05/25/34

   

192,841

   
 

470

   

  

   

6.50

   

11/25/35

   

86,858

   
 

2,963

   

EFMT, Class A1A (d)

   

4.50

(b)

 

03/25/54

   

2,617,761

   

EUR

244

    E-MAC DE 2005-I BV
3 Month EURIBOR + 0.50% (Germany)
   

12.075

(b)

 

05/25/52

   

254,387

   
 

1,000

    E-MAC DE BV, Class C,
3 Month EURIBOR + 1.40% (Germany)
   

9.195

(b)

 

11/25/54

   

564,218

   
 

114

    E-MAC NL 2004-I BV
3 Month EURIBOR + 0.18% (Netherlands)
   

6.208

(b)

 

07/25/36

   

118,847

   
 

71

    E-MAC NL 2005-I BV
3 Month EURIBOR + 0.23% (Netherlands)
   

8.382

(b)

 

04/25/38

   

66,396

   
 

143

    E-MAC Program BV
3 Month EURIBOR + 2.00% (Netherlands)
   

7.248

(b)

 

01/25/48

   

137,320

   
 

91

    E-MAC Program II BV
3 Month EURIBOR + 2.00% (Netherlands)
   

8.132

(b)

 

04/25/48

   

89,493

   
   

EMF-NL Prime BV

 
 

143

   

3 Month EURIBOR + 0.80% (Netherlands)

   

4.688

(b)

 

04/17/41

   

147,955

   
 

200

   

3 Month EURIBOR + 0.85% (Netherlands)

   

4.738

(b)

 

04/17/41

   

189,292

   
 

166

    Eurohome Mortgages PLC
3 Month EURIBOR + 0.21% (Ireland)
   

4.115

(b)

 

08/02/50

   

157,795

   

See Notes to Financial Statements
21


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 

EUR

500

    Eurosail-Nl 2007-1 BV
3 Month EURIBOR + 1.10% (Netherlands)
   

4.988

(b)%

 

04/17/40

 

$

519,343

   
   

Eurosail-NL 2007-2 BV

 
 

719

   

3 Month EURIBOR + 1.80% (Netherlands)

   

5.688

(b)

 

10/17/40

   

764,655

   
 

500

   

3 Month EURIBOR + 2.20% (Netherlands)

   

6.088

(b)

 

10/17/40

   

528,315

   
    Federal Home Loan Mortgage Corp. Whole Loan
Securities Trust
 

$

595

   

  

   

3.00

   

09/25/45 - 05/25/47

   

494,069

   
 

43

   

  

   

3.50

   

05/25/45

   

35,223

   
 

4,317

   

  

   

2.50

   

02/01/52 - 04/01/52

   

3,299,009

   
 

113

   

Flagstar Mortgage Trust, Class A3 (d)

   

3.00

(b)

 

03/25/50

   

85,641

   
 

617

   

Galton Funding Mortgage Trust (d)

   

4.00

(b)

 

02/25/59

   

570,563

   
   

Government National Mortgage Association

 
 

40

   

  

   

0.079

   

05/20/63

   

1,893

   
 

11

   

  

   

0.286

   

05/20/62

   

530

   
 

15

   

  

   

0.286

   

05/20/62

   

726

   
 

127

   

  

   

1.268

   

04/20/60

   

6,039

   
 

395

   

  

   

1.399

   

05/20/60

   

18,761

   
 

643

   

  

   

1.606

   

11/20/60

   

30,550

   

EUR

500

    Great Hall Mortgages No. 1 PLC
3 Month EURIBOR + 0.22% (United Kingdom)
   

4.148

(b)

 

03/18/39

   

520,297

   

$

115

   

GSAA Trust

   

6.00

   

04/01/34

   

111,764

   
   

GSR Mortgage Loan Trust

 
 

11

   

  

   

5.00

   

02/25/34

   

10,268

   
 

160

   

  

   

5.236

(b)

 

12/25/34

   

147,645

   
 

3

   

  

   

5.50

   

11/25/35

   

2,332

   
 

36

   

1 Month Term SOFR + 0.36%

   

5.681

(b)

 

03/25/35

   

22,194

   
 

253

   

  

   

6.00

   

09/25/35

   

241,860

   
 

3

    1 Year CMT + 1.75%    

6.75

(b)

 

03/25/33

   

3,057

   
 

84

   

HarborView Mortgage Loan Trust

   

5.838

(b)

 

05/19/33

   

77,565

   
   

Impac CMB Trust

 
 

778

   

1 Month Term SOFR + 0.63%

   

5.951

(b)

 

11/25/35

   

693,502

   
 

34

   

1 Month Term SOFR + 0.91%

   

6.226

(b)

 

10/25/34

   

33,942

   
 

391

   

IMS Ecuadorian Mortagage Trust (d)

   

3.40

   

08/18/43

   

382,782

   
 

73

   

IndyMac INDX Mortgage Loan Trust

   

6.495

(b)

 

11/25/34

   

70,023

   
   

JP Morgan Mortgage Trust

 
 

90

   

(d)

   

3.00

(b)

 

10/25/50

   

68,533

   
 

64

   

  

   

3.784

(b)

 

12/25/34

   

55,493

   
 

71

   

(d)

   

3.965

(b)

 

07/27/37

   

63,107

   

See Notes to Financial Statements
22


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 

EUR

140

    Lansdowne Mortgage Securities No. 1 PLC
3 Month EURIBOR + 0.30% (Ireland)
   

4.24

(b)%

 

06/15/45

 

$

144,014

   
 

308

    Lansdowne Mortgage Securities No. 2 PLC
3 Month EURIBOR + 0.34% (Ireland)
   

4.268

(b)

 

09/16/48

   

298,203

   
   

LHOME Mortgage Trust

     

$

1,500

   

(d)

   

7.628

   

11/25/28

   

1,522,191

   
 

2,375

   

(d)

   

8.00

   

06/25/28 - 08/25/28

   

2,417,229

   

GBP

360

    Mansard Mortgages PLC
3 Month GBP SONIA + 0.72% (United Kingdom)
   

5.952

(b)

 

10/15/48

   

421,027

   

$

188

   

MASTR Adjustable Rate Mortgages Trust

   

4.667

(b)

 

06/25/34

   

170,381

   
   

MASTR Alternative Loan Trust

     
 

119

   

  

   

5.00

   

05/25/18

   

104,986

   
 

80

   

  

   

6.00

   

05/25/33

   

73,898

   
 

1

   

MASTR Asset Securitization Trust

   

5.50

   

10/25/25

   

933

   
 

100

   

MASTR Reperforming Loan Trust (d)

   

7.50

   

05/25/35

   

75,510

   
 

393

    MERIT Securities Corp.
1 Month USD LIBOR + 2.25% (d)
   

7.683

(b)

 

09/28/32

   

354,519

   
   

Merrill Lynch Mortgage Investors Trust

     
 

7

   

  

   

4.43

(b)

 

01/25/37

   

6,936

   
 

9

   

6 Month Term SOFR + 0.93%

   

6.174

(b)

 

04/25/29

   

9,072

   
 

33

   

  

   

6.625

(b)

 

02/25/34

   

31,027

   
   

Miravet SARL - Compartment

     

EUR

1,000

   

3 Month EURIBOR + 1.60% (Spain)

   

5.545

(b)

 

05/26/65

   

1,063,493

   
 

500

   

3 Month EURIBOR + 2.00% (Spain)

   

5.945

(b)

 

05/26/65

   

523,392

   

$

62

   

Morgan Stanley Mortgage Loan Trust (See Note 9)

   

6.739

(b)

 

02/25/34

   

59,324

   
 

66

    Mortgage Equity Conversion Asset Trust
1 Year CMT + 0.47% (d)
   

5.64

(b)

 

02/25/42

   

65,791

   
 

56

   

National City Mortgage Capital Trust

   

6.00

   

03/25/38

   

51,885

   

GBP

345

    Newgate Funding PLC
3 Month GBP LIBOR + 3.12% (United Kingdom)
   

8.35

(b)

 

12/15/50

   

424,341

   

$

6,500

   

Ocwen Loan Investment Trust (d)

   

3.00

(b)

 

06/25/36 - 02/25/37

   

5,336,784

   
 

1,903

   

Onslow Bay Financial LLC, Class A1 (d)

   

3.00

(b)

 

01/25/52

   

1,539,102

   
 

849

   

PMC PLS ESR Issuer LLC (d)

   

5.114

   

02/25/27

   

828,902

   

EUR

491

    Portman Square IE, Class A,
3 Month EURIBOR + 3.50% (Ireland) (d)
   

7.382

(b)

 

07/25/63

   

525,722

   
   

PRET LLC

     

$

1,040

   

(d)

   

1.843

   

09/25/51

   

980,110

   
 

2,475

   

(d)

   

7.143

   

03/25/54

   

2,447,990

   
 

1,626

   

(d)

   

8.112

   

11/25/53

   

1,617,104

   

See Notes to Financial Statements
23


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 

$

757

   

PRKCM 2023-AFC1 Trust, Class A1 (d)

   

6.598

%

 

02/25/58

 

$

761,806

   
 

1,885

   

PRKCM Trust, Class A1 (d)

   

7.225

   

11/25/58

   

1,926,160

   
 

871

   

PRPM 2022-INV1 Trust (d)

   

4.40

   

04/25/67

   

839,975

   
   

PRPM LLC

     
 

1,019

   

(d)

   

3.75

   

03/25/54

   

888,998

   
 

1,829

   

(d)

   

4.00

   

11/25/53

   

1,734,478

   
 

1,949

   

(d)

   

6.959

   

02/25/29

   

1,926,776

   
 

39

   

RBSSP Resecuritization Trust (d)

   

81.666

(b)

 

09/26/37

   

150,776

   
 

13,196

   

Residential Asset Securitization Trust

   

0.50

   

04/25/37

   

220,265

   

EUR

309

    Resloc UK PLC
3 Month EURIBOR + 0.45% (United Kingdom)
   

4.39

(b)

 

12/15/43

   

300,129

   
   

RMF Buyout Issuance Trust

     

$

500

   

(d)

   

3.147

(b)

 

11/25/31

   

451,279

   
 

2,000

   

(d)

   

3.69

(b)

 

11/25/31

   

1,736,634

   
 

1,500

   

(d)

   

4.50

(b)

 

04/25/32

   

1,079,305

   
 

2,000

   

(d)

   

4.704

(b)

 

11/25/31

   

1,679,727

   
 

1,200

   

(d)

   

4.75

(b)

 

10/25/50

   

1,021,650

   
 

7,896

   

(d)

   

6.00

(b)

 

11/25/31 - 10/25/50

   

5,262,820

   
   

RMF Proprietary Issuance Trust

     
 

3,683

   

(d)

   

2.75

(b)

 

10/25/63

   

3,139,202

   
 

2,263

   

(d)

   

3.00

(b)

 

01/25/62

   

1,929,223

   
 

2,406

   

(d)

   

3.25

(b)

 

04/26/60

   

1,992,728

   
 

1,250

   

(d)

   

3.75

(b)

 

06/25/62

   

855,214

   
 

2,187

   

(d)

   

4.00

(b)

 

08/25/62

   

1,955,793

   
   

Seasoned Credit Risk Transfer Trust

     
 

13,316

   

  

   

3.00

   

09/25/55 - 11/25/63

   

11,071,658

   
 

1,976

   

  

   

3.25

   

07/25/56 - 06/25/57

   

1,724,215

   
 

892

   

  

   

3.50

   

07/25/58

   

760,840

   
 

1,470

   

  

   

4.00

   

03/25/58 - 02/25/59

   

1,336,406

   
 

3,180

   

(d)

   

4.25

(b)

 

08/25/59 - 05/25/60

   

2,873,414

   
 

256

   

  

   

4.50

   

06/25/57

   

245,456

   
 

3,950

   

(d)

   

4.75

(b)

 

07/25/58 - 10/25/58

   

3,711,330

   
 

60

    Sequoia Mortgage Trust
1 Month Term SOFR + 0.89%
   

6.21

(b)

 

01/20/36

   

43,457

   

AUD

500

    Solaris Trust
1 Month BBSW + 3.00% (Australia)
   

7.295

(b)

 

06/15/52

   

324,114

   

$

2,736

   

Stanwich Mortgage Loan Co. LLC (d)

   

2.735

   

10/16/26

   

2,621,487

   
   

Structured Adjustable Rate Mortgage Loan Trust

     
 

176

   

1 Month Term SOFR + 0.35%

   

5.671

(b)

 

03/25/35

   

159,347

   
 

155

   

  

   

6.332

(b)

 

02/25/35

   

150,860

   

See Notes to Financial Statements
24


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

PRINCIPAL
AMOUNT
(000)
 

  COUPON
RATE
  MATURITY
DATE
 

VALUE

 
   

Structured Asset Mortgage Investments II Trust

     

$

35

   

  

   

3.414

(b)%

 

04/19/35

 

$

30,264

   
 

77

   

1 Month Term SOFR + 0.57%

   

5.891

(b)

 

05/25/45

   

67,087

   
 

126

    Structured Asset Securities Corp. Mortgage
Pass-Through Certificates
   

6.311

(b)

 

11/25/30

   

121,030

   

EUR

450

    TDA 27 FTA
3 Month EURIBOR + 0.19% (Spain)
   

4.092

(b)

 

12/28/50

   

419,268

   

$

136

   

TIAA Bank Mortgage Loan Trust (d)

   

4.00

(b)

 

11/25/48

   

122,241

   
 

62

    Washington Mutual Mortgage Pass-Through
Certificates Trust
   

5.685

(b)

 

09/25/33

   

58,193

   
        Total Mortgages - Other (Cost $138,396,837)            

136,586,320

   
   

Short-Term Investments (18.0%)

     
   

Commercial Paper (0.6%)

     
 

2,000

    HSBC USA, Inc. (d)(e)
(Cost $1,962,507)
   

6.568

   

08/20/24

   

1,965,746

   
   

U.S. Treasury Securities (12.6%)

     
   

U.S. Treasury Bill,

     
 

4,000

   

(f)

   

5.242

   

7/5/24

   

3,962,011

   
 

3,000

   

(f)

   

5.304

   

9/19/24

   

2,938,959

   
 

5,000

   

(f)

   

5.306

   

6/20/24

   

4,964,594

   
 

5,434

   

(f)(g)

   

5.314

   

8/1/24

   

5,361,059

   
 

5,000

   

(f)

   

5.319

   

8/15/24

   

4,923,297

   
 

15,000

   

(f)

   

5.334

   

8/22/24

   

14,754,225

   
 

5,000

   

(f)

   

5.425

   

5/16/24

   

4,989,146

   
        Total U.S. Treasury Securities (Cost $41,903,433)            

41,893,291

   
NUMBER OF
SHARES
(000)
 

 

 

     
   

Investment Company (4.8%)

     
 

16,068

    Morgan Stanley Institutional Liquidity Funds - Government Portfolio -
Institutional Class, 5.23% (See Note 9) (Cost $16,068,246)
                   

16,068,246

   
        Total Short-Term Investments (Cost $59,934,186)            

59,927,283

   
        Total Investments (Cost $401,737,723) (h)(i)        

118.5

%

   

394,658,640

   
       

Liabilities in excess of Other Assets

       

(18.5

)

   

(61,556,135

)

 
       

Net Assets

       

100.0

%

 

$

333,102,505

   

See Notes to Financial Statements
25


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

  BBSW  Australia's Bank Bill Swap.

  CMT  Constant Maturity Treasury Note Rate.

  DAC  Designated Activity Company.

  EURIBOR  Euro Interbank Offered Rate.

  HECM  Home Equity Conversion Mortgage.

  IO  Interest Only Security.

  LIBOR  London Interbank Offered Rate.

  PAC  Planned Amortization Class.

  REMIC  Real Estate Mortgage Investment Conduit.

  SOFR  Secured Overnight Financing Rate.

  SOFR30A  30-Day Average Secured Overnight Financing Rate.

  SONIA  Sterling Overnight Index Average.

  STRIPS  Separate Trading of Registered Interest and Principal of Securities.

  TBA  To Be Announced.

  ‡  Amount is less than 0.05%.

  (a)  Security is subject to delayed delivery.

  (b)  Floating or variable rate securities: The rates disclosed are as of April 30, 2024. For securities based on a published reference rate and spread, the reference rate and spread are indicated in the description in the Portfolio of Investments. Certain variable rate securities may not be based on a published reference rate and spread but are determined by the issuer or agent and are based on current market conditions. These securities do not indicate a reference rate and spread in their description in the Portfolio of Investments.

  (c)  Inverse Floating Rate Security - Interest rate fluctuates with an inverse relationship to an associated interest rate. Indicated rate is the effective rate at April 30, 2024.

  (d)  144A security - Certain conditions for public sale may exist. Unless otherwise noted, these securities are deemed to be liquid.

  (e)  The rates shown are the effective yields at the date of purchase.

  (f)  Rate shown is the yield to maturity at April 30, 2024.

  (g)  All or a portion of the security was pledged to cover margin requirements for futures contracts.

  (h)  Securities are available for collateral in connection with securities purchased on a forward commitment basis, open foreign currency forward exchange contracts and futures contracts.

  (i)  At April 30, 2024, the aggregate cost for federal income tax purposes approximates the aggregate cost for book purposes. The aggregate gross unrealized appreciation is $6,665,457 and the aggregate gross unrealized depreciation is $16,367,068, resulting in net unrealized depreciation of $9,701,611.

Foreign Currency Forward Exchange Contracts:

The Fund had the following foreign currency forward exchange contracts open at April 30, 2024:

COUNTERPARTY

  CONTRACTS
TO DELIVER
  IN EXCHANGE
FOR
  DELIVERY
DATE
  UNREALIZED
APPRECIATION
(DEPRECIATION)
 

Bank of America NA

 

CAD

2,046,187

   

$

1,493,538

   

7/24/24

 

$

5,087

   

Bank of America NA

 

GBP

1,872,093

   

$

2,330,966

   

7/24/24

   

(9,387

)

 

BNP Paribas SA

 

AUD

402,074

   

$

260,149

   

7/24/24

   

(941

)

 

Royal Bank of Canada

 

EUR

329,717

   

$

353,809

   

7/24/24

   

688

   

UBS AG

 

EUR

14,425,043

   

$

15,483,827

   

7/24/24

   

34,872

   
   

$

30,319

   

See Notes to Financial Statements
26


Morgan Stanley Mortgage Securities Trust

Portfolio of Investments    April 30, 2024 (unaudited) continued

Futures Contracts:

The Fund had the following futures contracts open at April 30, 2024:

    NUMBER
OF
CONTRACTS
  EXPIRATION
DATE
  NOTIONAL
AMOUNT
(000)
 

VALUE

  UNREALIZED
DEPRECIATION
 

Long:

 

U.S. Treasury Long Bond (United States)

   

19

   

Jun-24

 

$

1,900

   

$

2,162,438

   

$

(81,195

)

 

U.S. Treasury 2 yr. Note (United States)

   

196

   

Jun-24

   

39,200

     

39,720,625

     

(266,155

)

 

U.S. Treasury 5 yr. Note (United States)

   

1,085

   

Jun-24

   

108,500

     

113,645,274

     

(1,972,778

)

 

U.S. Treasury 10 yr. Note (United States)

   

117

   

Jun-24

   

11,700

     

12,570,187

     

(332,719

)

 
   

$

(2,652,847

)

 

AUD  —  Australian Dollar

CAD  —  Canadian Dollar

EUR  —  Euro

GBP  —  British Pound

See Notes to Financial Statements
27


Morgan Stanley Mortgage Securities Trust

Financial Statements

Statement of Assets and Liabilities April 30, 2024 (unaudited)

Assets:

 

Investments in securities, at value (cost $385,607,109)

 

$

378,531,070

   

Investments in affiliates, at value (cost $16,130,614)

   

16,127,570

   

Total investments in securities, at value (cost $401,737,723)

   

394,658,640

   

Unrealized appreciation on open foreign currency forward exchange contracts

   

40,647

   

Cash (including foreign currency valued at $1,051,138 with a cost of $1,051,599)

   

1,051,138

   

Receivable for:

 

Investments sold

   

17,883,767

   

Interest

   

948,470

   

Shares of beneficial interest sold

   

696,584

   

Interest and dividends from affiliates

   

38,999

   

Prepaid expenses and other assets

   

113,253

   

Total Assets

   

415,431,498

   

Liabilities:

 

Payable to Bank

   

81,513

   

Unrealized depreciation on open foreign currency forward exchange contracts

   

10,328

   

Payable for:

 

Investments purchased

   

78,755,827

   

Shares of beneficial interest redeemed

   

2,495,732

   

Variation margin on open futures contracts

   

511,728

   

Advisory fee

   

103,606

   

Dividends to shareholders

   

92,925

   

Trustees' fees

   

36,238

   

Transfer and sub transfer agency fees

   

32,785

   

Administration fee

   

22,365

   

Distribution fee

   

13,015

   

Accrued expenses and other payables

   

172,931

   

Total Liabilities

   

82,328,993

   

Net Assets

 

$

333,102,505

   

Composition of Net Assets:

 

Paid-in-Capital

 

$

359,697,844

   

Total Accumulated Loss

   

(26,595,339

)

 

Net Assets

 

$

333,102,505

   

Class A Shares:

 

Net Assets

 

$

51,119,303

   
Shares Outstanding (unlimited shares authorized, $0.01 par value)    

6,829,510

   

Net Asset Value Per Share

 

$

7.49

   
Maximum Offering Price Per Share,
(net asset value plus 3.36% of net asset value)
 

$

7.74

   

Class L Shares:

 

Net Assets

 

$

286,850

   
Shares Outstanding (unlimited shares authorized, $0.01 par value)    

38,700

   

Net Asset Value Per Share

 

$

7.41

   

Class I Shares:

 

Net Assets

 

$

278,846,306

   
Shares Outstanding (unlimited shares authorized, $0.01 par value)    

37,832,980

   

Net Asset Value Per Share

 

$

7.37

   

Class C Shares:

 

Net Assets

 

$

2,839,165

   
Shares Outstanding (unlimited shares authorized, $0.01 par value)    

382,436

   

Net Asset Value Per Share

 

$

7.42

   

Class R6 Shares:

 

Net Assets

 

$

10,881

   
Shares Outstanding (unlimited shares authorized, $0.01 par value)    

1,480

   

Net Asset Value Per Share

 

$

7.35

   

See Notes to Financial Statements
28


Morgan Stanley Mortgage Securities Trust

Financial Statements continued

Statement of Operations For the six months ended April 30, 2024 (unaudited)

Net Investment Income:
Income
 

Interest

 

$

8,951,945

   

Interest and dividends from affiliates (Note 9)

   

263,148

   

Total Income

   

9,215,093

   

Expenses

 

Advisory fee (Note 4)

   

730,025

   

Administration fee (Note 4)

   

124,260

   

Professional fees

   

115,967

   

Sub transfer agency fees and expenses (Class A)

   

16,449

   

Sub transfer agency fees and expenses (Class L)

   

97

   

Sub transfer agency fees and expenses (Class I)

   

88,080

   

Sub transfer agency fees and expenses (Class C)

   

1,051

   

Distribution fee (Class A) (Note 5)

   

62,032

   

Distribution fee (Class L) (Note 5)

   

730

   

Distribution fee (Class C) (Note 5)

   

14,053

   

Registration fees

   

38,776

   

Custodian fees (Note 7)

   

29,380

   

Transfer agency fees and expenses (Class A) (Note 6)

   

11,173

   

Transfer agency fees and expenses (Class L) (Note 6)

   

1,166

   

Transfer agency fees and expenses (Class I) (Note 6)

   

7,280

   

Transfer agency fees and expenses (Class C) (Note 6)

   

1,247

   

Transfer agency fees and expenses (Class R6) (Note 6)

   

1,178

   

Shareholder reports and notices

   

20,971

   

Trustees' fees and expenses

   

2,959

   

Other

   

44,571

   

Total Expenses

   

1,311,445

   

Less: reimbursement of transfer agency and sub transfer agency fees (Note 4)

   

(175,265

)

 

Less: waiver of Advisory fees (Note 4)

   

(97,300

)

 

Less: reimbursement of class specific expenses (Class A) (Note 4)

   

(2,797

)

 

Less: reimbursement of class specific expenses (Class L) (Note 4)

   

(1,044

)

 

Less: reimbursement of class specific expenses (Class I) (Note 4)

   

(30,894

)

 

Less: reimbursement of class specific expenses (Class C) (Note 4)

   

(190

)

 

Less: reimbursement of class specific expenses (Class R6) (Note 4)

   

(1,178

)

 

Less: rebate from Morgan Stanley affiliated cash sweep (Note 9)

   

(7,776

)

 

Net Expenses

   

995,001

   

Net Investment Income

   

8,220,092

   
Realized and Unrealized Gain (Loss):
Realized Gain (Loss) on:
 

Investments

   

2,317,072

   

Investments in affiliates (Note 9)

   

(30

)

 

Foreign currency forward exchange contracts

   

743,584

   

Foreign currency translation

   

34,281

   

Futures contracts

   

(227,920

)

 

Net Realized Gain

   

2,866,987

   

Change in Unrealized Appreciation (Depreciation) on:

 

Investments

   

5,162,666

   

Investments in affiliates (Note 9)

   

725

   

Foreign currency forward exchange contracts

   

(887,193

)

 

Foreign currency translation

   

(155

)

 

Futures contracts

   

(464,138

)

 

Net Change in Unrealized Appreciation (Depreciation)

   

3,811,905

   

Net Gain

   

6,678,892

   

Net Increase in Net Assets Resulting from Operations

 

$

14,898,984

   

See Notes to Financial Statements
29


Morgan Stanley Mortgage Securities Trust

Financial Statements continued

Statements of Changes in Net Assets

    FOR THE SIX
MONTHS ENDED
APRIL 30, 2024
  FOR THE YEAR
ENDED
OCTOBER 31, 2023
 
   

(unaudited)

     
Increase (Decrease) in Net Assets:
Operations:
 

Net investment income

 

$

8,220,092

   

$

11,203,805

   

Net realized gain (loss)

   

2,866,987

     

(8,093,302

)

 

Net change in unrealized appreciation (depreciation)

   

3,811,905

     

851,537

   

Net Increase in Net Assets Resulting from Operations

   

14,898,984

     

3,962,040

   

Dividends and Distributions to Shareholders:

 

Class A

   

(1,208,388

)

   

(2,181,210

)

 

Class L

   

(6,753

)

   

(19,432

)

 

Class I

   

(6,789,001

)

   

(9,569,656

)

 

Class C

   

(57,896

)

   

(133,735

)

 

Class R6

   

(288

)

   

(599

)

 

Total Dividends and Distributions to Shareholders

   

(8,062,326

)

   

(11,904,632

)

 

Net increase from transactions in shares of beneficial interest

   

58,922,797

     

95,288,176

   

Net Increase

   

65,759,455

     

87,345,584

   

Net Assets:

 

Beginning of period

   

267,343,050

     

179,997,466

   

End of Period

 

$

333,102,505

   

$

267,343,050

   

See Notes to Financial Statements
30


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited)

1. Organization and Accounting Policies

Morgan Stanley Mortgage Securities Trust (the "Fund") is registered under the Investment Company Act of 1940, as amended (the "Act"), as a diversified, open-end management investment company. The Fund's investment objective is to seek a high level of current income. The Fund was organized as a Massachusetts business trust on November 20, 1986 and commenced operations on March 31, 1987. On July 28, 1997, the Fund converted to a multiple class share structure.

The Fund applies investment company accounting and reporting guidance Accounting Standard Codification ("ASC") Topic 946. In the preparation of these financial statements, management has evaluated subsequent events occurring after the date of the Fund's Statement of Assets and Liabilities through the date that the financial statements were issued.

The Fund offers Class A shares, Class L shares, Class I shares, Class C shares and Class R6 shares. Class C shares will automatically convert to Class A shares eight years after the end of the calendar month in which the shares were purchased. The five classes are substantially the same except that most Class A shares are subject to a sales charge imposed at the time of purchase, some Class A shares and most Class C shares are subject to a contingent deferred sales charge imposed on shares redeemed within one year. Class L shares, Class I shares and Class R6 shares are not subject to a sales charge. Additionally, Class A shares, Class L shares and Class C shares incur distribution expenses.

The Fund suspended offering Class L shares to all investors (April 30, 2015). Class L shareholders of the Fund do not have the option of purchasing additional Class L shares. However, the existing Class L shareholders may invest through reinvestment of dividends and distributions. In addition, Class L shares of the Fund may be exchanged for Class L shares of any Morgan Stanley Multi-Class Fund, even though Class L shares are closed to investors.

The following is a summary of significant accounting policies:

A. Valuation of Investments — (1) Fixed income securities may be valued by an outside pricing service/vendor approved by the Fund's Board of Trustees (the "Trustees"). The pricing service/vendor may employ a pricing model that takes into account, among other things, bids, yield spreads and/or other market data and specific security characteristics. If Morgan Stanley Investment Management Inc. (the "Adviser"), a wholly-owned subsidiary of Morgan Stanley, determines that the price provided by the outside pricing service/vendor does not reflect the security's fair value or is unable to provide a price, prices from brokers/dealers may also be utilized. In these circumstances, the value of the security will be the mean of bid and asked prices obtained from reputable brokers/dealers; (2) when market quotations are not readily available, as defined by Rule 2a-5 under the Act, including circumstances under which the Adviser, determines that the closing price, last sale price or the mean between the last


31


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

reported bid and asked prices are not reflective of a security's market value, portfolio securities are valued at their fair value as determined in good faith under procedures approved by and under the general supervision of the Trustees. Each business day, the Fund uses a third-party pricing service approved by the Trustees to assist with the valuation of foreign equity securities. Events occurring after the close of trading on foreign exchanges may result in adjustments to the valuation of foreign securities to reflect market trading that occurs after the close of the applicable foreign markets of comparable securities or other instruments that have a strong correlation to the fair-valued securities to more accurately reflect their fair value as of the close of regular trading on the NYSE; (3) futures are valued at the settlement price on the exchange on which they trade or, if a settlement price is unavailable, at the last sale price on the exchange; (4) foreign exchange transactions ("spot contracts") and foreign exchange forward contracts ("forward contracts") are valued daily using an independent pricing vendor at the spot and forward rates, respectively, as of the close of the NYSE; and (5) investments in mutual funds, including the Morgan Stanley Institutional Liquidity Funds, are valued at the net asset value ("NAV") as of the close of each business day.

In connection with Rule 2a-5 of the Act, the Trustees have designated the Fund's Adviser as its valuation designee. The valuation designee has responsibility for determining fair value and to make the actual calculations pursuant to the fair valuation methodologies previously approved by the Trustees. Under procedures approved by the Trustees, the Fund's Adviser, as valuation designee, has formed a Valuation Committee whose members are approved by the Trustees. The Valuation Committee provides administration and oversight of the Fund's valuation policies and procedures, which are reviewed at least annually by the Trustees. These procedures allow the Fund to utilize independent pricing services, quotations from securities and financial instrument dealers and other market sources to determine fair value.

B. Accounting for Investments — Security transactions are accounted for on the trade date (date the order to buy or sell is executed). Realized gains and losses on security transactions are determined by the identified cost method. Dividend income and other distributions are recorded on the ex-dividend date. Discounts are accreted and premiums are amortized over the life of the respective securities and are included in interest income. Interest income is accrued daily as earned.

C. When-Issued/Delayed Delivery Securities — The Fund may purchase or sell when-issued and delayed delivery securities. Securities purchased on a when-issued or delayed delivery basis are purchased for delivery beyond the normal settlement date at a stated price, and no income accrues to the Fund on such securities prior to delivery date. Payment and delivery for when-issued and delayed delivery securities can take place a month or more after the date of the transaction. When the Fund enters into a purchase transaction on a when-issued or delayed delivery basis, securities are available for collateral in an amount at least equal in value to the Fund's commitments to purchase such


32


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

securities. Purchasing securities on a when-issued or delayed delivery basis may involve a risk that the market price at the time of delivery may be lower than the agreed upon purchase price, in which case there could be an unrealized loss at the time of delivery. Purchasing investments on a when-issued or delayed delivery basis may be considered a form of leverage which may increase the impact that gains (losses) may have on the Fund.

D. Multiple Class Allocations — Investment income, realized and unrealized gain (loss) and non-class specific expenses are allocated daily based upon the proportion of net assets of each class. Class specific expenses are borne by the respective share classes and include Distribution, Transfer Agency, Sub Transfer Agency and Co-Transfer Agency fees.

E. Foreign Currency Translation and Foreign Investments — The books and records of the Fund are maintained in U.S. dollars. Foreign currency amounts are translated into U.S. dollars as follows:

— investments, other assets and liabilities at the prevailing rate of exchange on the valuation date;

— investment transactions and investment income at the prevailing rates of exchange on the dates of such transactions.

Although the net assets of the Fund are presented at the foreign exchange rates and market values at the close of the period, the Fund does not isolate that portion of the results of operations arising as a result of changes in the foreign exchange rates from the fluctuations arising from changes in the market prices of securities held at period end. Similarly, the Fund does not isolate the effect of changes in foreign exchange rates from the fluctuations arising from changes in the market prices of securities sold during the period. Accordingly, realized and unrealized foreign currency gains (losses) on investments in securities are included in the reported net realized and unrealized gains (losses) on investment transactions and balances. However, pursuant to U.S. federal income tax regulations, gains and losses from certain foreign currency transactions and the foreign currency portion of gains and losses realized on sales and maturities of foreign denominated debt securities are treated as ordinary income for U.S. federal income tax purposes.

Net realized gains (losses) on foreign currency transactions represent net foreign exchange gains (losses) from foreign currency forward exchange contracts, disposition of foreign currencies, currency gains (losses) realized between the trade and settlement dates on securities transactions, and the difference between the amount of investment income and foreign withholding taxes recorded on the Fund's books and the U.S. dollar equivalent amounts actually received or paid. The change in unrealized currency gains (losses) on foreign currency transactions for the period is reflected in the Statement of Operations.


33


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

F. Dividends and Distributions to Shareholders — Dividends and distributions to shareholders are recorded on the ex-dividend date. Dividends from net investment income, if any, are declared daily and paid monthly. Net realized capital gains, if any, are distributed at least annually.

G. Use of Estimates — The preparation of financial statements in accordance with generally accepted accounting principles in the United States ("GAAP") requires management to make estimates and assumptions that affect the reported amounts and disclosures. Actual results could differ from those estimates.

H. Indemnifications — The Fund enters into contracts that contain a variety of indemnification clauses. The Fund's maximum exposure under these arrangements is unknown as this would involve future claims that may be made against the Fund that have not yet occurred.

2. Fair Valuation Measurements

Financial Accounting Standards Board ("FASB") ASC 820, "Fair Value Measurement" ("ASC 820"), defines fair value as the price that would be received to sell an asset or pay to transfer a liability in an orderly transaction between market participants at the measurement date. ASC 820 establishes a three-tier hierarchy to distinguish between (1) inputs that reflect the assumptions market participants would use in valuing an asset or liability developed based on market data obtained from sources independent of the reporting entity (observable inputs); and (2) inputs that reflect the reporting entity's own assumptions about the assumptions market participants would use in valuing an asset or liability developed based on the best information available in the circumstances (unobservable inputs) and to establish classification of fair value measurements for disclosure purposes. Various inputs are used in determining the value of the Fund's investments. The inputs are summarized in the three broad levels listed below:

•  Level 1 — unadjusted quoted prices in active markets for identical investments

•  Level 2 — other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, credit risk, etc.)

•  Level 3 — significant unobservable inputs including the Fund's own assumptions in determining the fair value of investments. Factors considered in making this determination may include, but are not limited to, information obtained by contacting the issuer, analysts, or the appropriate stock exchange (for exchange-traded securities), analysis of the issuer's financial statements or other available documents and, if necessary, available information concerning other securities in similar circumstances.


34


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities and the determination of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to each security.

The following is a summary of the inputs used to value the Fund's investments as of April 30, 2024:

INVESTMENT TYPE

  LEVEL 1
UNADJUSTED
QUOTED
PRICES
  LEVEL 2
OTHER
SIGNIFICANT
OBSERVABLE
INPUTS
  LEVEL 3
SIGNIFICANT
UNOBSERVABLE
INPUTS
 

TOTAL

 

Assets:

 

Fixed Income Securities

 

Agency Adjustable Rate Mortgage

 

$

   

$

764,579

   

$

   

$

764,579

   

Agency Fixed Rate Mortgages

   

     

100,293,085

     

     

100,293,085

   

Asset-Backed Securities

   

     

64,376,553

     

     

64,376,553

   
Collateralized Mortgage Obligations —
Agency Collateral Series
   

     

15,047,391

     

     

15,047,391

   

Commercial Mortgage-Backed Securities

   

     

17,574,179

     

     

17,574,179

   

Corporate Bond

   

     

89,250

     

     

89,250

   

Mortgages — Other

   

     

136,586,320

     

     

136,586,320

   

Total Fixed Income Securities

   

     

334,731,357

     

     

334,731,357

   

Short-Term Investments

 

Commercial Paper

   

     

1,965,746

     

     

1,965,746

   

U.S. Treasury Securities

   

     

41,893,291

     

     

41,893,291

   

Investment Company

   

16,068,246

     

     

     

16,068,246

   

Total Short-Term Investments

   

16,068,246

     

43,859,037

     

     

59,927,283

   
Foreign Currency Forward Exchange
Contracts
   

     

40,647

     

     

40,647

   

Total Assets

   

16,068,246

     

378,631,041

     

     

394,699,287

   

Liabilities:

 
Foreign Currency Forward Exchange
Contracts
   

     

(10,328

)

   

     

(10,328

)

 

Futures Contracts

   

(2,652,847

)

   

     

     

(2,652,847

)

 

Total Liabilities

   

(2,652,847

)

   

(10,328

)

   

     

(2,663,175

)

 

Total

 

$

13,415,399

   

$

378,620,713

   

$

   

$

392,036,112

   

Transfers between investment levels may occur as the markets fluctuate and/or the availability of data used in an investment's valuation changes.


35


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

3. Derivatives

The Fund may, but it is not required to, use derivative instruments for a variety of purposes, including hedging, risk management, portfolio management or to earn income. Derivatives are financial instruments whose value is based, in part, on the value of an underlying asset, interest rate, index or financial instrument. Prevailing interest rates and volatility levels, among other things, also affect the value of derivative instruments. A derivative instrument often has risks similar to its underlying asset and may have additional risks, including imperfect correlation between the value of the derivative and the underlying asset, risks of default by the counterparty to certain transactions, magnification of losses incurred due to changes in the market value of the securities, instruments, indices or interest rates to which the derivative instrument relates, risks that the transactions may not be liquid, risks arising from margin and payment requirements, risks arising from mispricing or valuation complexity and operational and legal risks. The use of derivatives involves risks that are different from, and possibly greater than, the risks associated with other portfolio investments. Derivatives may involve the use of highly specialized instruments that require investment techniques and risk analyses different from those associated with other portfolio investments. All of the Fund's holdings, including derivative instruments, are marked-to-market each day with the change in value reflected in unrealized appreciation (depreciation). Upon disposition, a realized gain or loss is recognized.

Certain derivative transactions may give rise to a form of leverage. Leverage magnifies the potential for gain and risk of loss. Leverage associated with derivative transactions may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or may cause the Fund to be more volatile than if the Fund had not been leveraged. Although the Adviser seeks to use derivatives to further the Fund's investment objectives, there is no assurance that the use of derivatives will achieve this result.

Following is a description of the derivative instruments and techniques that the Fund used during the period and their associated risks:

Foreign Currency Forward Exchange Contracts — In connection with its investments in foreign securities, the Fund entered into contracts with banks, brokers/dealers to purchase or sell foreign currencies at a future date. A foreign currency forward exchange contract ("currency contract") is a negotiated agreement between the contracting parties to exchange a specified amount of currency at a specified future time at a specified rate. The rate can be higher or lower than the spot rate between the currencies that are the subject of the contract. Currency contracts may be used to protect against uncertainty in the level of future foreign currency exchange rates or to gain or modify exposure to a particular currency. To the extent hedged by the use of currency contracts, the precise matching of the currency contract amounts and the value of the securities involved will not generally be possible


36


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

because the future value of such securities in foreign currencies will change as a consequence of market movements in the value of those securities between the date on which the contract is entered into and the date it matures. Furthermore, such transactions may reduce or preclude the opportunity for gain if the value of the currency should move in the direction opposite to the position taken. There is additional risk to the extent that currency contracts create exposure to currencies in which the Fund's securities are not denominated. Unanticipated changes in currency prices may result in poorer overall performance for the Fund than if it had not entered into such contracts. The use of currency contracts involves the risk of loss from the insolvency or bankruptcy of the counterparty to the contract or the failure of the counterparty to make payments or otherwise comply with the terms of the contract. A currency contract is marked-to-market daily and the change in market value is recorded by the Fund as unrealized gain or loss. The Fund records realized gains (losses) when the currency contract is closed equal to the difference between the value of the currency contract at the time it was opened and the value at the time it was closed.

Futures — A futures contract is a standardized, exchange-traded agreement to buy or sell a specific quantity of an underlying asset, reference rate or index at a specific price at a specific future time. The value of a futures contract tends to increase and decrease in tandem with the value of the underlying instrument. Depending on the terms of the particular contract, futures contracts are settled through either physical delivery of the underlying instrument on the settlement date or by payment of a cash settlement amount on the settlement date. During the period the futures contract is open, payments are received from or made to the broker based upon changes in the value of the contract (the variation margin). A decision as to whether, when and how to use futures contracts involves the exercise of skill and judgment and even a well-conceived futures transaction may be unsuccessful because of market behavior or unexpected events. In addition to the derivatives risks discussed above, the prices of futures contracts can be highly volatile, using futures contracts can lower total return and the potential loss from futures contracts can exceed the Fund's initial investment in such contracts. No assurance can be given that a liquid market will exist for any particular futures contract at any particular time.

FASB ASC 815, "Derivatives and Hedging" ("ASC 815"), is intended to improve financial reporting about derivative instruments by requiring enhanced disclosures to enable investors to better understand how and why the Fund uses derivative instruments, how these derivative instruments are accounted for and their effects on the Fund's financial position and results of operations.


37


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

The following table sets forth the fair value of the Fund's derivative contracts by primary risk exposure as of April 30, 2024:

PRIMARY RISK EXPOSURE

  ASSET DERIVATIVES
STATEMENT OF ASSETS
AND LIABILITIES LOCATION
 

FAIR VALUE

  LIABILITY DERIVATIVES
STATEMENT OF ASSETS
AND LIABILITIES LOCATION
 

FAIR VALUE

 
Currency Risk
 
 
 
  Unrealized appreciation on
open foreign currency
forward exchange
contracts
 

$

40,647

    Unrealized depreciation on
open foreign currency
forward exchange
contracts
 

$

(10,328

)

 
Interest Rate Risk
 
  Variation margin on open
futures contracts
   

    Variation margin on open
futures contracts
   

(2,652,847

)(a)

 
       

$

40,647

       

$

(2,663,175

)

 

(a)  Includes cumulative appreciation (depreciation) as reported in the Portfolio of Investments. Only current day's net variation margin is reported within the Statement of Assets and Liabilities.

The following tables set forth by primary risk exposure the Fund's realized gains (losses) and change in unrealized appreciation (depreciation) by type of derivative contract for the six months ended April 30, 2024 in accordance with ASC 815:

AMOUNT OF REALIZED GAIN (LOSS) ON DERIVATIVES

PRIMARY RISK EXPOSURE

 

FUTURES CONTRACTS

  FOREIGN CURRENCY
FORWARD EXCHANGE
CONTRACTS
 

Interest Rate Risk

 

$

(227,920

)

 

$

   

Currency Risk

   

     

743,584

   

Total

 

$

(227,920

)

 

$

743,584

   

CHANGE IN UNREALIZED APPRECIATION (DEPRECIATION) ON DERIVATIVES

PRIMARY RISK EXPOSURE

 

FUTURES CONTRACTS

  FOREIGN CURRENCY
FORWARD EXCHANGE
CONTRACTS
 

Interest Rate Risk

 

$

(464,138

)

 

$

   

Currency Risk

   

     

(887,193

)

 

Total

 

$

(464,138

)

 

$

(887,193

)

 


38


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

At April 30, 2024, the Fund's derivative assets and liabilities are as follows:

GROSS AMOUNTS OF ASSETS AND LIABILITIES PRESENTED IN THE STATEMENT OF ASSETS AND LIABILITIES

DERIVATIVES(a)

 

ASSETS(b)

 

LIABILITIES(b)

 

Foreign Currency Forward Exchange Contracts

 

$

40,647

   

$

(10,328

)

 

(a)  Excludes exchange-traded derivatives.

(b)  Absent an event of default or early termination, over-the-counter ("OTC") derivative assets and liabilities are presented gross and not offset in the Statement of Assets and Liabilities.

The Fund typically enters into International Swaps and Derivatives Association, Inc. Master Agreements ("ISDA Master Agreements") or similar master agreements (collectively, "Master Agreements") with its contract counterparties for certain OTC derivatives in order to, among other things, reduce its credit risk to counterparties. ISDA Master Agreements include provisions for general obligations, representations, collateral and events of default or termination. Under an ISDA Master Agreement, the Fund typically may offset with the counterparty certain OTC derivative financial instruments' payables and/or receivables with collateral held and/or posted and create one single net payment (close-out netting) in the event of default, termination and/or potential deterioration in the credit quality of the counterparty. Various Master Agreements govern the terms of certain transactions with counterparties, including transactions such as swap, forward, repurchase and reverse repurchase agreements. These Master Agreements typically attempt to reduce the counterparty risk associated with such transactions by specifying credit protection mechanisms and providing standardization that improves legal certainty. Cross-termination provisions under Master Agreements typically provide that a default in connection with one transaction between the Fund and a counterparty gives the non-defaulting party the right to terminate any other transactions in place with the defaulting party to create one single net payment due to/due from the defaulting party and may be a feature in certain Master Agreements. In the event the Fund exercises its right to terminate a Master Agreement after a counterparty experiences a termination event as defined in the Master Agreement, the return of collateral with market value in excess of the Fund's net liability may be delayed or denied.


39


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

The following tables present derivative financial instruments that are subject to enforceable netting arrangements as of April 30, 2024:

GROSS AMOUNTS NOT OFFSET IN THE STATEMENT OF ASSETS AND LIABILITIES

COUNTERPARTY

  GROSS ASSET DERIVATIVES
PRESENTED IN THE STATEMENT
OF ASSETS AND LIABILITIES
  FINANCIAL
INSTRUMENT
  COLLATERAL
RECEIVED
  NET AMOUNT
(NOT LESS THAN $0)
 

Bank of America NA

 

$

5,087

   

$

(5,087

)

 

$

   

$

0

   

Royal Bank of Canada

   

688

     

     

     

688

   

UBS AG

   

34,872

     

     

     

34,872

   

Total

 

$

40,647

   

$

(5,087

)

 

$

   

$

35,560

   

GROSS AMOUNTS NOT OFFSET IN THE STATEMENT OF ASSETS AND LIABILITIES

COUNTERPARTY

  GROSS LIABILITY DERIVATIVES
PRESENTED IN THE STATEMENT
OF ASSETS AND LIABILITIES
  FINANCIAL
INSTRUMENT
  COLLATERAL
PLEDGED
  NET AMOUNT
(NOT LESS THAN $0)
 

Bank of America NA

 

$

9,387

   

$

(5,087

)

 

$

   

$

4,300

   

BNP Paribas SA

   

941

     

     

     

941

   

Total

 

$

10,328

   

$

(5,087

)

 

$

   

$

5,241

   

For the six months ended April 30, 2024, the average monthly amount outstanding for each derivative type is as follows:

Foreign Currency Forward Exchange Contracts:

 

Average monthly principal amount

 

$

21,927,417

   

Futures Contracts:

 

Average monthly notional value

 

$

138,976,616

   

4. Advisory/Administration Agreements

Pursuant to an Investment Advisory Agreement with the Adviser, the Fund pays an advisory fee, accrued daily and paid monthly, by applying the following annual rates to the net assets of the Fund determined as of the close of each business day: 0.47% to the portion of the daily net assets not exceeding $1 billion; 0.445% to the portion of the daily net assets exceeding $1 billion but not exceeding $1.5 billion; 0.42% to the portion of the daily net assets exceeding $1.5 billion but not exceeding $2 billion; 0.395% to the portion of the daily net assets exceeding $2 billion but not exceeding $2.5 billion; 0.37% to the portion of the daily net assets exceeding $2.5 billion but not exceeding $5 billion; 0.345% to the portion of the daily net assets exceeding $5 billion but not exceeding $7.5 billion; 0.32% to the portion of the daily net assets exceeding $7.5 billion but not exceeding $10 billion; 0.295% to the portion of the daily net assets exceeding $10 billion but not exceeding $12.5 billion; and 0.27% to the portion of the daily net assets exceeding $12.5 billion. For the six months ended April 30, 2024, the advisory fee rate (net of


40


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

waiver/rebate) was equivalent to an annual effective rate of 0.40% of the Fund's average daily net assets.

The Adviser also serves as the Administrator to the Fund and provides administrative services pursuant to an Administration Agreement for an annual fee, accrued daily and paid monthly, of 0.08% of the Fund's average daily net assets.

Under a Sub-Administration Agreement between the Administrator and State Street Bank and Trust Company ("State Street"), State Street provides certain administrative services to the Fund. For such services, the Administrator pays State Street a portion of the fee the Administrator receives from the Fund.

The Adviser/Administrator has agreed to reduce its advisory fee, its administration fee and/or reimburse the Fund so that total annual operating expenses, excluding certain investment related expenses, taxes, interest and other extraordinary expenses (including litigation), will not exceed 1.00% for Class A, 1.30% for Class L, 0.70% for Class I, 1.80% for Class C and 0.65% for Class R6. These fee waivers and/or expense reimbursements will continue for at least one year from the date of the Fund's prospectus or until such time that the Trustees act to discontinue all or a portion of such waivers and/or expense reimbursements when they deem such action is appropriate. For the six months ended April 30, 2024, $97,300 of advisory fees were waived and $36,103 of other expenses were reimbursed by the Adviser pursuant to this arrangement.

The Adviser agreed to reimburse the Fund for prior years overpayment of transfer agency and sub transfer agency fees. This was reflected as "reimbursement of transfer agency and sub transfer agency fees" in the Statement of Operations.

5. Plan of Distribution

Shares of the Fund are distributed by Morgan Stanley Distribution, Inc. (the "Distributor"), an affiliate of the Adviser/Administrator. The Fund has adopted a Plan of Distribution (the "Plan") pursuant to Rule 12b-1 under the Act. The Plan provides that the Fund will pay the Distributor a fee which is accrued daily and paid monthly at the following annual rates: (i) Class A — up to 0.25% of the average daily net assets of Class A shares; (ii) Class L — up to 0.50% of the average daily net assets of Class L shares; and (iii) Class C — up to 1.00% of the average daily net assets of Class C shares.

In the case of Class A shares, Class L shares and Class C shares, expenses incurred pursuant to the Plan in any calendar year in excess of 0.25%, 0.50% and 1.00% of the average daily net assets of Class A shares, Class L shares and Class C shares, respectively, will not be reimbursed by the Fund


41


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

through payments in any subsequent year. For the six months ended April 30, 2024, the distribution fee was accrued for Class A shares, Class L shares and Class C shares at the annual rate of 0.25%, 0.50% and 1.00%, respectively.

The Distributor has informed the Fund that for the six months ended April 30, 2024, it received contingent deferred sales charges from certain redemptions of the Fund's Class A shares of $2,028, and received $10,610 in front-end sales charges from sales of the Fund's Class A shares. The respective shareholders pay such charges, which are not an expense of the Fund.

6. Dividend Disbursing and Transfer/Co-Transfer Agent

The Fund's dividend disbursing and transfer agent is SS&C Global Investor & Distribution Solutions, Inc. ("SS&C GIDS"). Pursuant to a Transfer Agency Agreement, the Fund pays SS&C GIDS a fee based on the number of classes, accounts and transactions relating to the Fund.

Eaton Vance Management ("EVM"), an affiliate of Morgan Stanley, provides co-transfer agency and related services to the Fund pursuant to a Co-Transfer Agency Services Agreement. For the six months ended April 30, 2024, co-transfer agency fees and expenses incurred to EVM, included in "Transfer agent fees and expenses" in the Statement of Operations, amounted to $2,330.

7. Custodian Fees

State Street (the "Custodian") also serves as Custodian for the Fund in accordance with a Custodian Agreement. The Custodian holds cash, securities and other assets of the Fund as required by the Act. Custody fees are payable monthly based on assets held in custody, investment purchases and sales activity and account maintenance fees, plus reimbursement for certain out-of-pocket expenses.


42


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

8. Shares of Beneficial Interest

Transactions in shares of beneficial interest, including direct exchanges pursuant to share class conversions for all periods presented, were as follows:

    FOR THE SIX
MONTHS ENDED
APRIL 30, 2024
  FOR THE YEAR
ENDED
OCTOBER 31, 2023
 
   

(unaudited)

     
   

SHARES

 

AMOUNT

 

SHARES

 

AMOUNT

 

CLASS A SHARES

 

Sold

   

1,067,814

   

$

8,122,894

     

2,195,154

   

$

16,477,927

   

Reinvestment of dividends and distributions

   

156,704

     

1,192,190

     

286,895

     

2,159,494

   

Redeemed

   

(598,894

)

   

(4,548,792

)

   

(1,574,634

)

   

(11,788,800

)

 

Net increase — Class A

   

625,624

     

4,766,292

     

907,415

     

6,848,621

   

CLASS L SHARES

 

Reinvestment of dividends and distributions

   

882

     

6,640

     

2,589

     

19,341

   

Redeemed

   

(1,285

)

   

(9,705

)

   

(65,954

)

   

(495,867

)

 

Net decrease — Class L

   

(403

)

   

(3,065

)

   

(63,365

)

   

(476,526

)

 

CLASS I SHARES

 

Sold

   

14,235,790

     

106,345,022

     

25,780,390

     

192,429,657

   

Reinvestment of dividends and distributions

   

903,789

     

6,768,903

     

1,289,336

     

9,537,130

   

Redeemed

   

(7,952,420

)

   

(59,285,235

)

   

(15,160,414

)

   

(112,574,912

)

 

Net increase — Class I

   

7,187,159

     

53,828,690

     

11,909,312

     

89,391,875

   

CLASS C SHARES

 

Sold

   

119,333

     

904,341

     

61,081

     

459,076

   

Reinvestment of dividends and distributions

   

7,662

     

57,822

     

17,980

     

134,411

   

Redeemed

   

(83,201

)

   

(631,573

)

   

(144,347

)

   

(1,069,882

)

 

Net increase (decrease) — Class C

   

43,794

     

330,590

     

(65,286

)

   

(476,395

)

 

CLASS R6 SHARES

 

Reinvestment of dividends and distributions

   

39

     

290

     

81

     

601

   

Net increase in Fund

   

7,856,213

   

$

58,922,797

     

12,688,157

   

$

95,288,176

   

9. Security Transactions and Transactions with Affiliates

The cost of purchases and proceeds from sales of investment securities, excluding short-term investments, for the six months ended April 30, 2024, aggregated $615,518,222 and $552,016,972, respectively. Included in the aforementioned are purchases and sales of U.S. Government securities of $531,499,184 and $500,117,409, respectively.

The Fund invests in the Institutional Class of the Morgan Stanley Institutional Liquidity Funds — Government Portfolio (the "Liquidity Fund"), an open-end management investment company managed by


43


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

the Adviser. Advisory fees paid by the Fund are reduced by an amount equal to its pro-rata share of the advisory and administration fees paid by the Fund due to its investment in the Liquidity Fund. For the six months ended April 30, 2024, advisory fees paid were reduced by $7,776 relating to the Fund's investment in the Liquidity Fund.

The Fund had transactions with Morgan Stanley and its affiliated broker-dealers, which may be deemed affiliates of the Adviser/Administrator and Distributor under Section 17 the Act.

A summary of the Fund's transactions in shares of affiliated investments during the six months ended April 30, 2024 is as follows:

AFFILIATED
INVESTMENT
COMPANY/
ISSUER
  VALUE
OCTOBER 31,
2023
  PURCHASES
AT COST
  PROCEEDS
FROM SALES/
PAYDOWNS
  DIVIDEND/
INTEREST
INCOME
  REALIZED
GAIN
(LOSS)
  CHANGE IN
UNREALIZED
APPRECIATION
(DEPRECIATION)
  VALUE
APRIL 30,
2024
 

Liquidity Fund

 

$

7,021,923

   

$

131,578,376

   

$

122,532,053

   

$

260,974

   

$

   

$

   

$

16,068,246

   
Morgan
Stanley
Mortgage
Loan Trust
   

63,255

     

     

4,626

     

2,174

     

(30

)

   

725

     

59,324

   

Total

 

$

7,085,178

   

$

131,578,376

   

$

122,536,679

   

$

263,148

   

$

(30

)

 

$

725

   

$

16,127,570

   

The Fund has an unfunded noncontributory defined benefit pension plan covering certain independent Trustees of the Fund who will have served as independent Trustees for at least five years at the time of retirement. Benefits under this plan are based on factors which include years of service and compensation. The Trustees voted to close the plan to new participants and eliminate the future benefits growth due to increases to compensation after July 31, 2003. Aggregate pension costs for the six months ended April 30, 2024, included in "Trustees' fees and expenses" in the Statement of Operations amounted to $852. At April 30, 2024, the Fund had an accrued pension liability of $36,238, which is reflected as "Trustees' fees" in the Statement of Assets and Liabilities.

The Fund has an unfunded Deferred Compensation Plan (the "Compensation Plan"), which allows each independent Trustee to defer payment of all, or a portion, of the fees he or she receives for serving on the Board of Trustees. Each eligible Trustee generally may elect to have the deferred amounts credited with a return equal to the total return on one or more of the Morgan Stanley funds that are offered as investment options under the Compensation Plan. Appreciation/depreciation and distributions received from these investments are recorded with an offsetting increase/decrease in the deferred compensation obligation and do not affect the NAV of the Fund.


44


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

10. Federal Income Tax Status

It is the Fund's intention to continue to qualify as a regulated investment company and distribute all of its taxable and tax-exempt income. Accordingly, no provision for federal income taxes is required in the financial statements.

The Fund may be subject to taxes imposed by countries in which it invests. Such taxes are generally based on income and/or capital gains earned or repatriated. Taxes are accrued based on net investment income, net realized gains and net unrealized appreciation as such income and/or gains are earned. Taxes may also be based on transactions in foreign currency and are accrued based on the value of investments denominated in such currency.

FASB ASC 740-10, "Income Taxes — Overall", sets forth a minimum threshold for financial statement recognition of the benefit of a tax position taken or expected to be taken in a tax return. Management has concluded there are no significant uncertain tax positions that would require recognition in the financial statements. If applicable, the Fund recognizes interest accrued related to unrecognized tax benefits in "Interest Expense" and penalties in "Other Expenses" in the Statement of Operations. The Fund files tax returns with the U.S. Internal Revenue Service, New York and various states. Generally, each of the tax years in the four-year period ended October 31, 2023 remains subject to examination by taxing authorities.

The tax character of distributions paid may differ from the character of distributions shown for GAAP purposes due to short-term capital gains being treated as ordinary income for tax purposes. The tax character of distributions paid during fiscal years 2023 and 2022 was as follows:

  2023 DISTRIBUTIONS PAID FROM:

 

2022 DISTRIBUTIONS PAID FROM:

 

ORDINARY
INCOME

 

LONG-TERM
CAPITAL GAIN

 

ORDINARY
INCOME

 

$

11,904,632

   

$

   

$

6,135,808

   

The amount and character of income and gains to be distributed are determined in accordance with income tax regulations which may differ from GAAP. These book/tax differences are either considered temporary or permanent in nature.

Temporary differences are attributable to differing book and tax treatments for the timing of the recognition of gains (losses) on certain investment transactions and the timing of the deductibility of certain expenses.


45


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

Permanent differences, due to a nondeductible expense, resulted in the following reclassifications among the components of net assets at October 31, 2023:

TOTAL
ACCUMULATED
LOSS
  PAID-IN-
CAPITAL
 

$

23,325

   

$

(23,325

)

 

At October 31, 2023, the components of distributable earnings for the Fund on a tax basis were as follows:

UNDISTRIBUTED
ORDINARY
INCOME
  UNDISTRIBUTED
LONG-TERM
CAPITAL GAIN
 

$

1,230,748

   

$

   

At October 31, 2023, the Fund had available for federal income tax purposes unused short-term and long-term capital losses of $12,538,063 and $9,598,994, respectively, that do not have an expiration date.

To the extent that capital loss carryforwards are used to offset any future capital gains realized, no capital gains tax liability will be incurred by the Fund for gains realized and not distributed. To the extent that capital gains are offset, such gains will not be distributed to the shareholders.

11. Market Risk and Risks Relating to Certain Financial Instruments

The Fund may invest in mortgage securities, including securities issued by the Federal National Mortgage Association ("FNMA") and Federal Home Loan Mortgage Corporation ("FHLMC"). These are fixed income securities that derive their value from or represent interests in a pool of mortgages or mortgage securities. An unexpectedly high rate of defaults on the mortgages held by a mortgage pool may adversely affect the value of a mortgage-backed security and could result in losses to the Fund. The risk of such defaults is generally higher in the case of mortgage pools that include sub-prime mortgages. Sub-prime mortgages refer to loans made to borrowers with weakened credit histories or with a lower capacity to make timely payments on their mortgages. The securities held by the Fund are not backed by sub-prime mortgages.

Additionally, securities issued by FNMA and FHLMC are not backed by or entitled to the full faith and credit of the United States; rather, they are supported by the right of the issuer to borrow from the U.S. Department of the Treasury.


46


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

The Federal Housing Finance Agency ("FHFA") serves as conservator of FNMA and FHLMC and the U.S. Department of the Treasury has agreed to provide capital as needed to ensure FNMA and FHLMC continue to provide liquidity to the housing and mortgage markets.

Foreign security and currency transactions may involve certain considerations and risks not typically associated with those of U.S. dollar denominated transactions as a result of, among other factors, fluctuations of exchange rates in relation to the U.S. dollar, the possibility of lower levels of governmental supervision and regulation of foreign securities markets and the possibility of political or economic instability.

The value of an investment in the Fund is based on the values of the Fund's investments, which change due to economic and other events that affect markets generally, as well as those that affect particular regions, countries, industries, companies or governments. The risks associated with these developments may be magnified if certain social, political, economic and other conditions and events adversely interrupt the global economy and financial markets. Securities in the Fund's portfolio may underperform due to inflation (or expectations for inflation), interest rates, global demand for particular products or resources, natural disasters and extreme weather events, health emergencies (such as epidemics and pandemics), terrorism, regulatory events and governmental or quasi-governmental actions. The occurrence of global events similar to those in recent years, such as terrorist attacks around the world, natural disasters, health emergencies, social and political (including geopolitical) discord and tensions or debt crises and downgrades, among others, may result in market volatility and may have long term effects on both the U.S. and global financial markets. The occurrence of such events may be sudden and unexpected, and it is difficult to predict when similar events affecting the U.S. or global financial markets may occur, the effects that such events may have and the duration of those effects (which may last for extended periods). Any such event(s) could have a significant adverse impact on the value, liquidity and risk profile of the Fund's portfolio, as well as its ability to sell securities and/or meet redemptions. Any such event(s) or similar types of factors and developments may also adversely affect the financial performance of the Fund's investments (and, in turn, the Fund's investment results) and/or negatively impact broad segments of businesses and populations and have a significant and rapid negative impact on the performance of the Fund's investments, and exacerbate preexisting risks to the Fund.

12. Credit Facility

The Fund and other Morgan Stanley funds participated in a $500,000,000 committed, unsecured revolving line of credit facility (the "Facility") with State Street. This Facility is to be used for temporary emergency purposes or funding of shareholder redemption requests. The interest rate for any funds drawn will be based on the federal funds rate or overnight bank funding rate plus a spread. The Facility


47


Morgan Stanley Mortgage Securities Trust

Notes to Financial Statements    April 30, 2024 (unaudited) continued

also has a commitment fee of 0.25% per annum based on the unused portion of the Facility, which is allocated among participating funds based on relative net assets. During the six months ended April 30, 2024, the Fund did not have any borrowings under the Facility.

13. Other

At April 30, 2024, the Fund had record owners of 10% or greater. Investment activities of these shareholders could have a material impact on the Fund. The aggregate percentage of such owners was 77.5%.

14. LIBOR Discontinuance or Unavailability Risk

The Fund's investments, payment obligations and financing terms may be based on floating rates, such as the London Interbank Offered Rates (collectively, "LIBOR"), Euro Interbank Offered Rate, Secured Overnight Financing Rate ("SOFR") and other similar types of reference rates (each, a "Reference Rate"). These Reference Rates are generally intended to represent the rate at which contributing banks may obtain short-term borrowings from each other within certain financial markets. LIBOR was the basic rate of interest used in lending transactions between banks on the London interbank market and was widely used as a reference for setting the interest rate on loans globally. As a result of benchmark reforms, publication of most LIBOR settings has ceased. However, the publication of certain other LIBORs will continue to be published on a temporary, synthetic and non-representative basis (e.g., the 1-month, 3-month, and 6-month USD LIBOR settings which are expected to be continued to be published until the end of September 2024). As these synthetic LIBOR settings are expected to be published for a limited period of time and are considered non-representative of the underlying market, regulators have advised that these settings should be used only in limited circumstances. Various financial industry groups have been planning for the transition from LIBOR and certain regulators and industry groups have taken actions to establish alternative reference rates (e.g., the SOFR, which measures the cost of overnight borrowings through repurchase agreement transactions collateralized with U.S. Treasury securities and is intended to replace U.S. dollar LIBORs with certain adjustments).There is no assurance that the composition or characteristics of any such alternative reference rate will be similar to or produce the same value or economic equivalence as LIBOR or that it will have the same volume or liquidity as did LIBOR. These developments could negatively impact financial markets in general and present heightened risks, including with respect to the Fund's investments. As a result of the uncertainty and developments relating to the transition process, performance, price volatility, liquidity and value of the Fund and its assets may be adversely affected.


48


Morgan Stanley Mortgage Securities Trust

Financial Highlights

Selected ratios and per share data for a share of beneficial interest outstanding throughout each period:

   

FOR THE SIX

 

FOR THE YEAR ENDED OCTOBER 31,

 
   

MONTHS ENDED

     
   

APRIL 30, 2024

 

2023

 

2022

 

2021

 

2020

 

2019

 
   

(unaudited)

                     

Class A Shares

 

Selected Per Share Data:

 

Net asset value, beginning of period

 

$

7.27

   

$

7.43

   

$

8.60

   

$

8.62

   

$

8.79

   

$

8.39

   

Income (loss) from investment operations:

 

Net investment income

   

0.19

     

0.37

     

0.26

     

0.20

     

0.24

     

0.26

   

Net realized and unrealized gain (loss)

   

0.21

     

(0.13

)

   

(1.17

)

   

(0.02

)

   

(0.07

)

   

0.41

   
Total income (loss) from investment
operations
   

0.40

     

0.24

     

(0.91

)

   

0.18

     

0.17

     

0.67

   

Less distributions from:

 

Net investment income

   

(0.18

)

   

(0.40

)

   

(0.26

)

   

(0.20

)

   

(0.31

)

   

(0.27

)

 

Net realized gain

   

     

     

     

     

(0.03

)

   

   

Total distributions

   

(0.18

)

   

(0.40

)

   

(0.26

)

   

(0.20

)

   

(0.34

)

   

(0.27

)

 

Net asset value, end of period

 

$

7.49

   

$

7.27

   

$

7.43

   

$

8.60

   

$

8.62

   

$

8.79

   

Total Return

   

5.54

%(1)(2)(3)    

3.19

%(2)    

(10.77

)%(2)    

2.04

%(4)    

2.09

%(4)    

8.04

%(2)  

Ratios to Average Net Assets:

 

Net expenses

   

0.87

%(5)(6)(7)(8)    

1.00

%(7)(8)    

0.99

%(7)(8)    

0.99

%(7)(8)    

0.99

%(7)(8)    

0.98

%(7)(8)  

Net investment income

   

5.06

%(5)(6)(7)(8)    

4.98

%(7)(8)    

3.15

%(7)(8)    

2.25

%(7)(8)    

2.84

%(7)(8)    

3.10

%(7)(8)  

Rebate from Morgan Stanley affiliate

   

0.01

%(6)    

0.00

%(9)    

0.01

%

   

0.01

%

   

0.01

%

   

0.02

%

 

Supplemental Data:

 

Net assets, end of period, in thousands

 

$

51,119

   

$

45,123

   

$

39,360

   

$

51,289

   

$

48,756

   

$

64,085

   

Portfolio turnover rate

   

179

%(3)    

429

%

   

334

%

   

317

%

   

233

%

   

261

%

 

(1)  Refer to Note 4 in the Notes to Financial Statements for discussion of prior period transfer agency and sub transfer agency fees that were reimbursed in the current period. The amount of the reimbursement was immaterial on a per share basis and the impact was less than 0.005% to the total return of Class A shares.

(2)  Does not reflect the deduction of sales charge. Calculated based on the net asset value as of the last business day of the period.

(3)  Not annualized.

(4)  Calculated using the NAV for US GAAP financial reporting purposes and as such differs from the total return presented in the Fund Report and Performance Summary. Does not reflect the deduction of sales charge.

(5)  If the Fund had not received the reimbursement of transfer agency and sub transfer agency fees from the Adviser, the net expenses and net investment income/loss ratios, would have been as follows for Class A shares:

PERIOD ENDED   EXPENSE
RATIO
  NET INVESTMENT
INCOME RATIO
 
April 30, 2024    

0.99

%

   

4.94

%

 

(6)  Annualized.

(7)  If the Fund had borne all of its expenses that were waived by the Adviser/Administrator, the annualized expense and net investment income ratios would have been as follows:

PERIOD ENDED   EXPENSE
RATIO
  NET INVESTMENT
INCOME RATIO
 
April 30, 2024    

1.07

%

   

4.86

%

 

October 31, 2023

   

1.20

     

4.78

   

October 31, 2022

   

1.19

     

2.95

   

October 31, 2021

   

1.15

     

2.09

   

October 31, 2020

   

1.16

     

2.67

   

October 31, 2019

   

1.20

     

2.88

   

(8)  The ratios reflect the rebate of certain Fund expenses in connection with investments in a Morgan Stanley affiliate during the period. The effect of the rebate on the ratios is disclosed in the above table as "Rebate from Morgan Stanley affiliate."

(9)  Amount is less than 0.005%.

See Notes to Financial Statements
49


Morgan Stanley Mortgage Securities Trust

Financial Highlights continued

   

FOR THE SIX

 

FOR THE YEAR ENDED OCTOBER 31,

 
   

MONTHS ENDED

     
   

APRIL 30, 2024

 

2023

 

2022

 

2021

 

2020

 

2019

 
   

(unaudited)

                     

Class L Shares

 

Selected Per Share Data:

 

Net asset value, beginning of period

 

$

7.20

   

$

7.37

   

$

8.52

   

$

8.55

   

$

8.71

   

$

8.31

   

Income (loss) from investment operations:

 

Net investment income

   

0.18

     

0.35

     

0.24

     

0.17

     

0.22

     

0.23

   

Net realized and unrealized gain (loss)

   

0.20

     

(0.14

)

   

(1.15

)

   

(0.03

)

   

(0.06

)

   

0.41

   
Total income (loss) from investment
operations
   

0.38

     

0.21

     

(0.91

)

   

0.14

     

0.16

     

0.64

   

Less distributions from:

 

Net investment income

   

(0.17

)

   

(0.38

)

   

(0.24

)

   

(0.17

)

   

(0.29

)

   

(0.24

)

 

Net realized gain

   

     

     

     

     

(0.03

)

   

   

Total distributions

   

(0.17

)

   

(0.38

)

   

(0.24

)

   

(0.17

)

   

(0.32

)

   

(0.24

)

 

Net asset value, end of period

 

$

7.41

   

$

7.20

   

$

7.37

   

$

8.52

   

$

8.55

   

$

8.71

   

Total Return

   

5.30

%(1)(2)(3)    

2.83

%(1)    

(10.90

)%(1)    

1.64

%(4)    

1.93

%(4)    

7.81

%(1)  

Ratios to Average Net Assets:

 

Net expenses

   

1.17

%(5)(6)(7)(8)    

1.29

%(7)(8)    

1.29

%(7)(8)    

1.29

%(7)(8)    

1.29

%(7)(8)    

1.28

%(7)(8)  

Net investment income

   

4.76

%(5)(6)(7)(8)    

4.68

%(7)(8)    

2.88

%(7)(8)    

1.99

%(7)(8)    

2.58

%(7)(8)    

2.84

%(7)(8)  

Rebate from Morgan Stanley affiliate

   

0.00

%(6)(9)    

0.01

%

   

0.01

%

   

0.01

%

   

0.01

%

   

0.02

%

 

Supplemental Data:

 

Net assets, end of period, in thousands

 

$

287

   

$

282

   

$

755

   

$

996

   

$

1,144

   

$

1,167

   

Portfolio turnover rate

   

179

%(3)    

429

%

   

334

%

   

317

%

   

233

%

   

261

%

 

(1)  Calculated based on the net asset value as of the last business day of the period.

(2)  Refer to Note 4 in the Notes to Financial Statements for discussion of prior period transfer agency and sub transfer agency fees that were reimbursed in the current period. The amount of the reimbursement was immaterial on a per share basis and the impact was less than 0.005% to the total return of Class L shares.

(3)  Not annualized.

(4)  Calculated using the NAV for US GAAP financial reporting purposes and as such differs from the total return presented in the Fund Report and Performance Summary.

(5)  If the Fund had not received the reimbursement of transfer agency and sub transfer agency fees from the Adviser, the net expenses and net investment income/loss ratios, would have been as follows for Class L shares:

PERIOD ENDED   EXPENSE
RATIO
  NET INVESTMENT
INCOME RATIO
 
April 30, 2024    

1.29

%

   

4.64

%

 

(6)  Annualized.

(7)  If the Fund had borne all of its expenses that were waived by the Adviser/Administrator, the annualized expense and net investment income ratios would have been as follows:

PERIOD ENDED   EXPENSE
RATIO
  NET INVESTMENT
INCOME RATIO
 
April 30, 2024    

2.08

%

   

3.85

%

 

October 31, 2023

   

2.22

     

3.75

   

October 31, 2022

   

1.67

     

2.50

   

October 31, 2021

   

1.61

     

1.67

   

October 31, 2020

   

1.53

     

2.34

   

October 31, 2019

   

1.71

     

2.41

   

(8)  The ratios reflect the rebate of certain Fund expenses in connection with investments in a Morgan Stanley affiliate during the period. The effect of the rebate on the ratios is disclosed in the above table as "Rebate from Morgan Stanley affiliate."

(9)  Amount is less than 0.005%.

See Notes to Financial Statements
50


Morgan Stanley Mortgage Securities Trust

Financial Highlights continued

   

FOR THE SIX

 

FOR THE YEAR ENDED OCTOBER 31,

 
   

MONTHS ENDED

     
   

APRIL 30, 2024

 

2023

 

2022

 

2021

 

2020

 

2019

 
   

(unaudited)

                     

Class I Shares

 

Selected Per Share Data:

 

Net asset value, beginning of period

 

$

7.16

   

$

7.31

   

$

8.45

   

$

8.48

   

$

8.64

   

$

8.24

   

Income (loss) from investment operations:

 

Net investment income

   

0.20

     

0.39

     

0.28

     

0.23

     

0.27

     

0.28

   

Net realized and unrealized gain (loss)

   

0.21

     

(0.12

)

   

(1.14

)

   

(0.04

)

   

(0.06

)

   

0.41

   
Total income (loss) from investment
operations
   

0.41

     

0.27

     

(0.86

)

   

0.19

     

0.21

     

0.69

   

Less distributions from:

 

Net investment income

   

(0.20

)

   

(0.42

)

   

(0.28

)

   

(0.22

)

   

(0.34

)

   

(0.29

)

 

Net realized gain

   

     

     

     

     

(0.03

)

   

   

Total distributions

   

(0.20

)

   

(0.42

)

   

(0.28

)

   

(0.22

)

   

(0.37

)

   

(0.29

)

 

Net asset value, end of period

 

$

7.37

   

$

7.16

   

$

7.31

   

$

8.45

   

$

8.48

   

$

8.64

   

Total Return

   

5.65

%(1)(2)(3)    

3.58

%(1)    

(10.33

)%(1)    

2.28

%(4)    

2.58

%(4)    

8.53

%(1)  

Ratios to Average Net Assets:

 

Net expenses

   

0.58

%(5)(6)(7)(8)    

0.70

%(7)(8)    

0.69

%(7)(8)    

0.69

%(7)(8)    

0.69

%(7)(8)    

0.69

%(7)(8)  

Net investment income

   

5.35

%(5)(6)(7)(8)    

5.27

%(7)(8)    

3.57

%(7)(8)    

2.59

%(7)(8)    

3.20

%(7)(8)    

3.42

%(7)(8)  

Rebate from Morgan Stanley affiliate

   

0.01

%(6)    

0.00

%(9)    

0.01

%

   

0.01

%

   

0.01

%

   

0.01

%

 

Supplemental Data:

 

Net assets, end of period, in thousands

 

$

278,846

   

$

219,485

   

$

136,895

   

$

135,147

   

$

116,307

   

$

125,752

   

Portfolio turnover rate

   

179

%(3)    

429

%

   

334

%

   

317

%

   

233

%

   

261

%

 

(1)  Calculated based on the net asset value as of the last business day of the period.

(2)  Refer to Note 4 in the Notes to Financial Statements for discussion of prior period transfer agency and sub transfer agency fees that were reimbursed in the current period. The amount of the reimbursement was immaterial on a per share basis and the impact was less than 0.005% to the total return of Class I shares.

(3)  Not annualized.

(4)  Calculated using the NAV for US GAAP financial reporting purposes and as such differs from the total return presented in the Fund Report and Performance Summary.

(5)  If the Fund had not received the reimbursement of transfer agency and sub transfer agency fees from the Adviser, the net expenses and net investment income/loss ratios, would have been as follows for Class I shares:

PERIOD ENDED   EXPENSE
RATIO
  NET INVESTMENT
INCOME RATIO
 
April 30, 2024    

0.69

%

   

5.24

%

 

(6)  Annualized.

(7)  If the Fund had borne all of its expenses that were waived by the Adviser/Administrator, the annualized expense and net investment income ratios would have been as follows:

PERIOD ENDED   EXPENSE
RATIO
  NET INVESTMENT
INCOME RATIO
 
April 30, 2024    

0.79

%

   

5.14

%

 

October 31, 2023

   

0.91

     

5.06

   

October 31, 2022

   

0.91

     

5.06

   

October 31, 2021

   

0.87

     

2.41

   

October 31, 2020

   

0.91

     

2.98

   

October 31, 2019

   

0.94

     

3.17

   

(8)  The ratios reflect the rebate of certain Fund expenses in connection with investments in a Morgan Stanley affiliate during the period. The effect of the rebate on the ratios is disclosed in the above table as "Rebate from Morgan Stanley affiliate."

(9)  Amount is less than 0.005%.

See Notes to Financial Statements
51


Morgan Stanley Mortgage Securities Trust

Financial Highlights continued

   

FOR THE SIX

 

FOR THE YEAR ENDED OCTOBER 31,

 
   

MONTHS ENDED

     
   

APRIL 30, 2024

 

2023

 

2022

 

2021

 

2020

 

2019

 
   

(unaudited)

                     

Class C Shares

 

Selected Per Share Data:

 

Net asset value, beginning of period

 

$

7.21

   

$

7.37

   

$

8.53

   

$

8.55

   

$

8.72

   

$

8.32

   

Income (loss) from investment operations:

 

Net investment income

   

0.16

     

0.31

     

0.20

     

0.13

     

0.18

     

0.19

   

Net realized and unrealized gain (loss)

   

0.20

     

(0.13

)

   

(1.16

)

   

(0.02

)

   

(0.07

)

   

0.41

   
Total income (loss) from investment
operations
   

0.36

     

0.18

     

(0.96

)

   

0.11

     

0.11

     

0.60

   

Less distributions from:

 

Net investment income

   

(0.15

)

   

(0.34

)

   

(0.20

)

   

(0.13

)

   

(0.25

)

   

(0.20

)

 

Net realized gain

   

     

     

     

     

(0.03

)

   

   

Total distributions

   

(0.15

)

   

(0.34

)

   

(0.20

)

   

(0.13

)

   

(0.28

)

   

(0.20

)

 

Net asset value, end of period

 

$

7.42

   

$

7.21

   

$

7.37

   

$

8.53

   

$

8.55

   

$

8.72

   

Total Return

   

5.18

%(1)(2)(3)    

2.41

%(2)    

(11.46

)%(2)    

1.25

%(4)    

1.33

%(4)    

7.31

%(2)  

Ratios to Average Net Assets:

 

Net expenses

   

1.67

%(5)(6)(7)(8)    

1.80

%(7)(8)    

1.79

%(7)(8)    

1.79

%(7)(8)    

1.76

%(7)(8)    

1.74

%(7)(8)  

Net investment income

   

4.26

%(5)(6)(7)(8)    

4.17

%(7)(8)    

2.45

%(7)(8)    

1.52

%(7)(8)    

2.10

%(7)(8)    

2.36

%(7)(8)  

Rebate from Morgan Stanley affiliate

   

0.01

%(6)    

0.00

%(9)    

0.01

%

   

0.01

%

   

0.01

%

   

0.02

%

 

Supplemental Data:

 

Net assets, end of period, in thousands

 

$

2,839

   

$

2,443

   

$

2,978

   

$

2,695

   

$

5,110

   

$

6,176

   

Portfolio turnover rate

   

179

%(3)    

429

%

   

334

%

   

317

%

   

233

%

   

261

%

 

(1)  Refer to Note 4 in the Notes to Financial Statements for discussion of prior period transfer agency and sub transfer agency fees that were reimbursed in the current period. The amount of the reimbursement was immaterial on a per share basis and the impact was less than 0.005% to the total return of Class C shares.

(2)  Does not reflect the deduction of sales charge. Calculated based on the net asset value as of the last business day of the period.

(3)  Not annualized.

(4)  Calculated using the NAV for US GAAP financial reporting purposes and as such differs from the total return presented in the Fund Report and Performance Summary.

(5)  If the Fund had not received the reimbursement of transfer agency and sub transfer agency fees from the Adviser, the net expenses and net investment income/loss ratios, would have been as follows for Class C shares:

PERIOD ENDED   EXPENSE
RATIO
  NET INVESTMENT
INCOME RATIO
 
April 30, 2024    

1.79

%

   

4.14

%

 

(6)  Annualized.

(7)  If the Fund had borne all of its expenses that were waived by the Adviser/Administrator, the annualized expense and net investment income ratios would have been as follows:

PERIOD ENDED   EXPENSE
RATIO
  NET INVESTMENT
INCOME RATIO
 
April 30, 2024    

1.88

%

   

4.05

%

 

October 31, 2023

   

2.01

     

3.96

   

October 31, 2022

   

1.98

     

2.26

   

October 31, 2021

   

1.94

     

1.37

   

October 31, 2020

   

1.90

     

1.96

   

October 31, 2019

   

1.92

     

2.18

   

(8)  The ratios reflect the rebate of certain Fund expenses in connection with investments in a Morgan Stanley affiliate during the period. The effect of the rebate on the ratios is disclosed in the above table as "Rebate from Morgan Stanley affiliate."

(9)  Amount is less than 0.005%.

See Notes to Financial Statements
52


Morgan Stanley Mortgage Securities Trust

Financial Highlights continued

   

FOR THE SIX

 

FOR THE YEAR ENDED OCTOBER 31,

 
   

MONTHS ENDED

     
   

APRIL 30, 2024

 

2023

 

2022

 

2021

 

2020

 

2019

 
   

(unaudited)

                     
Class R6 Shares(1)  

Selected Per Share Data:

 

Net asset value, beginning of period

 

$

7.15

   

$

7.30

   

$

8.45

   

$

8.47

   

$

8.64

   

$

8.24

   

Income (loss) from investment operations:

 

Net investment income

   

0.20

     

0.39

     

0.29

     

0.23

     

0.27

     

0.29

   

Net realized and unrealized gain (loss)

   

0.20

     

(0.11

)

   

(1.15

)

   

(0.03

)

   

(0.07

)

   

0.41

   
Total income (loss) from investment
operations
   

0.40

     

0.28

     

(0.86

)

   

0.20

     

0.20

     

0.70

   

Less distributions from:

 

Net investment income

   

(0.20

)

   

(0.43

)

   

(0.29

)

   

(0.22

)

   

(0.34

)

   

(0.30

)

 

Net realized gain

   

     

     

     

     

(0.03

)

   

   

Total distributions

   

(0.20

)

   

(0.43

)

   

(0.29

)

   

(0.22

)

   

(0.37

)

   

(0.30

)

 

Net asset value, end of period

 

$

7.35

   

$

7.15

   

$

7.30

   

$

8.45

   

$

8.47

   

$

8.64

   

Total Return

   

5.55

%(2)(3)(4)    

3.76

%(2)    

(10.41

)%(2)    

2.43

%(5)    

2.51

%(5)    

8.58

%(2)  

Ratios to Average Net Assets:

 

Net expenses

   

0.53

%(6)(7)(8)(9)    

0.65

%(8)(9)    

0.64

%(8)(9)    

0.65

%(8)(9)    

0.64

%(8)(9)    

0.63

%(8)(9)  

Net investment income

   

5.40

%(6)(7)(8)(9)    

5.33

%(8)(9)    

3.59

%(8)(9)    

2.63

%(8)(9)    

3.26

%(8)(9)    

3.53

%(8)(9)  

Rebate from Morgan Stanley affiliate

   

0.01

%(7)    

0.00

%(10)    

0.01

%

   

0.00

%(10)    

0.01

%

   

0.02

%

 

Supplemental Data:

 

Net assets, end of period, in thousands

 

$

11

   

$

10

   

$

10

   

$

11

   

$

11

   

$

11

   

Portfolio turnover rate

   

179

%(4)    

429

%

   

334

%

   

317

%

   

233

%

   

261

%

 

(1)  Effective April 29, 2022, Class IS shares were renamed Class R6 shares.

(2)  Calculated based on the net asset value as of the last business day of the period.

(3)  Refer to Note 4 in the Notes to Financial Statements for discussion of prior period transfer agency and sub transfer agency fees that were reimbursed in the current period. The amount of the reimbursement was immaterial on a per share basis and the impact was less than 0.005% to the total return of Class R6 shares.

(4)  Not annualized.

(5)  Calculated using the NAV for US GAAP financial reporting purposes and as such differs from the total return presented in the Fund Report and Performance Summary.

(6)  If the Fund had not received the reimbursement of transfer agency and sub transfer agency fees from the Adviser, the net expenses and net investment income/loss ratios, would have been as follows for Class R6 shares:

PERIOD ENDED   EXPENSE
RATIO
  NET INVESTMENT
INCOME RATIO
 
April 30, 2024    

0.64

%

   

5.29

%

 

(7)  Annualized.

(8)  If the Fund had borne all of its expenses that were waived by the Adviser/Administrator, the annualized expense and net investment loss ratios would have been as follows:

PERIOD ENDED   EXPENSE
RATIO
  NET INVESTMENT
LOSS RATIO
 
April 30, 2024    

22.50

%

   

(16.57

)%

 

October 31, 2023

   

26.50

     

(20.52

)

 

October 31, 2022

   

20.23

     

(16.00

)

 

October 31, 2021

   

20.64

     

(17.36

)

 

October 31, 2020

   

19.93

     

(16.03

)

 

October 31, 2019

   

21.33

     

(17.17

)

 

(9)  The ratios reflect the rebate of certain Fund expenses in connection with investments in a Morgan Stanley affiliate during the period. The effect of the rebate on the ratios is disclosed in the above table as "Rebate from Morgan Stanley affiliate."

(10)  Amount is less than 0.005%.

See Notes to Financial Statements
53


Morgan Stanley Mortgage Securities Trust

Liquidity Risk Management Program (unaudited)

In compliance with Rule 22e-4 under the Investment Company Act of 1940, as amended (the "Liquidity Rule"), the Fund has adopted and implemented a liquidity risk management program (the "Program"), which is reasonably designed to assess and manage the risk that the Fund could not meet requests to redeem shares issued by the Fund without significant dilution of remaining investors' interests in the Fund (i.e., liquidity risk). The Fund's Board of Trustees (the "Board") previously approved the designation of the Liquidity Risk Subcommittee (the "LRS") as Program administrator. The LRS is comprised of representatives from various divisions within Morgan Stanley Investment Management.

At a meeting held on March 1-2, 2024, the Board reviewed a written report prepared by the LRS that addressed the Program's operation and assessed its adequacy, and effectiveness of implementation for the period from January 1, 2023, through December 31, 2023, as required under the Liquidity Rule. The report concluded that the Program operated effectively and was adequately and effectively implemented in all material aspects, and that the relevant controls and safeguards were appropriately designed to enable the LRS to administer the Program in compliance with the Liquidity Rule.

In accordance with the Program, the LRS assessed each Fund's liquidity risk no less frequently than annually taking into consideration certain factors, as applicable, such as (i) investment strategy and liquidity of portfolio investments, (ii) short-term and long-term cash flow projections and (iii) holdings of cash and cash equivalents and borrowing arrangements and other funding sources. Certain factors are considered under both normal and reasonably foreseeable stressed conditions.

Each Fund portfolio investment is classified into one of four liquidity categories, which classification is assessed at least monthly by the LRS. The classification is based on a determination of the number of days it is reasonably expected to take to convert the investment into cash, or sell or dispose of the investment, in current market conditions without significantly changing the market value of the investment. Liquidity classification determinations take into account various market, trading and investment-specific considerations, as well as market depth, and in some cases utilize third-party vendor data.

The Liquidity Rule limits a fund's investments in illiquid investments to 15% of its net assets and requires funds that do not primarily hold assets that are highly liquid investments to determine and maintain a minimum percentage of the fund's net assets to be invested in highly liquid investments (highly liquid investment minimum or "HLIM"). The LRS believes that the Program includes provisions reasonably designed to review, monitor and comply with the 15% limit on illiquid investments and for determining, periodically reviewing and complying with the HLIM requirement, as applicable.

There can be no assurance that the Program will achieve its objectives under all circumstances in the future. Please refer to the Fund's prospectus for more information regarding the Fund's exposure to liquidity risk and other risks to which it may be subject.


54


Morgan Stanley Mortgage Securities Trust

Important Notices (unaudited)

Reporting to Shareholders

Each Morgan Stanley fund provides a complete schedule of portfolio holdings in its semi-annual and annual reports within 60 days of the end of the fund's second and fourth fiscal quarters. The semi-annual and annual reports are filed electronically with the Securities and Exchange Commission ("SEC") on Form N-CSRS and Form N-CSR, respectively. Morgan Stanley makes these reports available on its public website, www.morganstanley.com/im. Each Morgan Stanley non-money market fund also files a complete schedule of portfolio holdings with the SEC for the fund's first and third fiscal quarters as an attachment to Form N-PORT and monthly holding for each money market fund on Form N-MFP. Morgan Stanley does not deliver the reports for the first and third fiscal quarters to shareholders, but makes the complete schedule of portfolio holdings for the fund's first and third fiscal quarters available on its public website. The holdings for each money market fund are also posted to the Morgan Stanley public website. You may, however, obtain Form N-PORT filings (as well as the Form N-CSR, N-CSRS and N-MFP filings) by accessing the SEC's website, www.sec.gov. You can also request copies of these materials, upon payment of a duplicating fee, by electronic request at the SEC's email address (publicinfo@sec.gov).

Proxy Voting Policy and Proxy Voting Record

The Board of Trustees believes that the voting of proxies on securities held by the Fund is an important element of the overall investment process. As such, the Trustees have delegated the responsibility to vote such proxies to the Adviser.

A copy of the Proxy Policy, as well as the Fund's most recent proxy voting record for the 12-month period ended June 30, as filed with the SEC, are available without charge on our website at www.morganstanley.com/im. The Fund's proxy voting record is also available without charge on the SEC's website at www.sec.gov.

Householding Notice

To reduce printing and mailing costs, the Fund attempts to eliminate duplicate mailings to the same address. The Fund delivers a single copy of certain shareholder documents, including shareholder reports, prospectuses and proxy materials, to investors with the same last name who reside at the same address. Your participation in this program will continue for an unlimited period of time unless you instruct us otherwise. You can request multiple copies of these documents by calling 1 (800) 869-6397, 8:00 a.m. to 6:00 p.m., ET. Once our Customer Service Center has received your instructions, we will begin sending individual copies for each account within 30 days.


55


Morgan Stanley Mortgage Securities Trust

Important Notices (unaudited) continued

Tailored Shareholder Reports

Effective January 24, 2023, the SEC adopted rule and form amendments to require open-end mutual funds and ETFs to transmit concise and visually engaging streamlined annual and semi-annual reports to shareholders that highlight key information. Other information, including financial statements, will no longer appear in a streamlined shareholder report but must be available online, delivered free of charge upon request, and filed on a semi-annual basis on Form N-CSR. The rule and form amendments have a compliance date of July 24, 2024. At this time, management is evaluating the impact of these amendments on the shareholder reports for the Morgan Stanley Funds.


56


Morgan Stanley Mortgage Securities Trust

U.S. Customer Privacy Notice (unaudited)   February 2024

FACTS

 

WHAT DOES MSIM DO WITH YOUR PERSONAL INFORMATION?

 

Why?

 

Financial companies choose how they share your personal information. Federal law gives consumers the right to limit some but not all sharing. Federal law also requires us to tell you how we collect, share, and protect your personal information. Please read this notice carefully to understand what we do.

 

What?

  The types of personal information we collect and share depend on the product or service you have with us. This information can include:
Social Security number and income
investment experience and risk tolerance
checking account number and wire transfer instructions
 

How?

 

All financial companies need to share customers' personal information to run their everyday business. In the section below, we list the reasons financial companies can share their customers' personal information; the reasons MSIM chooses to share; and whether you can limit this sharing.

 

 

Reasons we can share your personal information

 

Does MSIM share?

 

Can you limit this sharing?

 
For our everyday business purposes —
such as to process your transactions, maintain your account(s), respond to court orders and legal investigations, or report to credit bureaus
 

Yes

 

No

 
For our marketing purposes —
to offer our products and services to you
 

Yes

 

No

 

For joint marketing with other financial companies

 

No

 

We don't share

 
For our affiliates' everyday business purposes —
information about your transactions and experiences
 

Yes

 

No*

 
For our affiliates' everyday business purposes —
information about your creditworthiness
 

Yes

 

Yes*

 

For our affiliates to market to you

 

Yes

 

Yes*

 

For non-affiliates to market to you

 

No

 

We don't share

 


57


Morgan Stanley Mortgage Securities Trust

U.S. Customer Privacy Notice (unaudited) continued   February 2024

To limit our sharing

  Call toll-free (844) 312-6327 or email: imprivacyinquiries@morganstanley.com
Please note:
If you are a new customer, we can begin sharing your information 30 days from the date we sent this notice. When you are no longer our customer, we continue to share your information as described in this notice. However, you can contact us at any time to limit our sharing.
 

Questions?

 

Call toll-free (844) 312-6327 or email: imprivacyinquiries@morganstanley.com

 

Who we are

Who is providing this notice?

  Morgan Stanley Investment Management Inc. and its investment management affiliates ("MSIM") (See Affiliates definition below.)  

What we do

How does MSIM protect my personal information?

 

To protect your personal information from unauthorized access and use, we use security measures that comply with federal law. These measures include computer safeguards and secured files and buildings. We have policies governing the proper handling of customer information by personnel and requiring third parties that provide support to adhere to appropriate security standards with respect to such information.

 

How does MSIM collect my personal information?

  We collect your personal information, for example, when you
open an account or make deposits or withdrawals from your account
buy securities from us or make a wire transfer
give us your contact information
We also collect your personal information from others, such as credit bureaus, affiliates, or other companies.
 

Why can't I limit all sharing?

  Federal law gives you the right to limit only
sharing for affiliates' everyday business purposes — information about your creditworthiness
affiliates from using your information to market to you
sharing for non-affiliates to market to you
State laws and individual companies may give you additional rights to limit sharing. (See below for more on your rights under state law.)
 


58


Morgan Stanley Mortgage Securities Trust

U.S. Customer Privacy Notice (unaudited) continued   February 2024

What we do

What happens when I limit sharing for an account I hold jointly with someone else?

 

Your choices will apply to everyone on your account.

 

Definitions

Affiliates

  Companies related by common ownership or control. They can be financial and non-financial companies.
Our affiliates include registered investment advisers such as Eaton Vance Management and Calvert Research and Management, registered broker-dealers such as Morgan Stanley Distributors Inc. and Eaton Vance Distributors, Inc., and registered and unregistered funds sponsored by Morgan Stanley Investment Management such as the registered funds within Morgan Stanley Institutional Fund, Inc. (together, the "Investment Management Affiliates"); and companies with a Morgan Stanley name and financial companies such as Morgan Stanley Barney LLC and Morgan Stanley & Co. (the, "Morgan Stanley Affiliates").
 

Non-affiliates

  Companies not related by common ownership or control. They can be financial and non-financial companies.
MSIM does not share with non-affiliates so they can market to you.
 

Joint marketing

  A formal agreement between non-affiliated financial companies that together market financial products or services to you.
MSIM doesn't jointly market
 

Other important information

* Please Note: MSIM does not share your creditworthiness information or your transactions and experiences information with the Morgan Stanley Affiliates, nor does MSIM enable the Morgan Stanley Affiliates to market to you. Your opt outs will prevent MSIM from sharing your creditworthiness information with the Investment management Affiliates and will prevent the investment Management Affiliates from marketing their products to you.

Vermont: Except as permitted by law, we will not share personal information we collect about Vermont residents with Non-affiliates unless you provide us with your written consent to share such information.

California: Except as permitted by law, we will not share personal information we collect about California residents with Non-affiliates and we will limit sharing such personal information with our Affiliates to comply with California privacy laws that apply to us.


59


Trustees

Frank L. Bowman

Frances L. Cashman

Kathleen A. Dennis

Nancy C. Everett

Richard G. Gould

Eddie A. Grier

Jakki L. Haussler

Dr. Manuel H. Johnson

Michael F. Klein

Patricia A. Maleski

W. Allen Reed, Chair of the Board

Officers

Deidre A. Downes
Chief Compliance Officer

John H. Gernon
President and Principal Executive Officer

Michael J. Key
Vice President

Mary E. Mullin
Secretary and Chief Legal Officer

Francis J. Smith
Treasurer and Principal Financial Officer

Transfer Agent

SS&C Global Investor & Distribution Solutions, Inc.
333 W 11th Street
Kansas City, Missouri 64105

Co-Transfer Agent

Eaton Vance Management
One Post Office Square
Suite 1600
Boston, Massachusetts 02109

Custodian

State Street Bank and Trust Company
One Congress Street
Boston, Massachusetts 02114

Independent Registered Public Accounting Firm

Ernst & Young LLP
200 Clarendon Street
Boston, Massachusetts 02116

Legal Counsel

Dechert LLP
1095 Avenue of the Americas
New York, New York 10036

Counsel to the Independent Trustees

Morgan, Lewis & Bockius LLP
One State Street
Hartford, Connecticut 06103

Adviser and Administrator

Morgan Stanley Investment Management Inc.
1585 Broadway
New York, New York 10036

Distributor

Morgan Stanley Distribution, Inc.
1585 Broadway
New York, New York 10036

This report is submitted for the general information of the shareholders of the Fund. For more detailed information about the Fund, its fees and expenses and other pertinent information, please read its Prospectus. The Fund's Statement of Additional Information contains additional information about the Fund, including its Trustees. It is available, without charge, by calling 1 (800) 869-6397.

This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by an effective Prospectus. Please read the Prospectus carefully before investing.

Morgan Stanley Distribution, Inc., member FINRA.

© 2024 Morgan Stanley

MTGSAN
6650340 EXP 06.30.25


 

Item 2. Code of Ethics.

 

Not applicable for semiannual reports.
 

Item 3. Audit Committee Financial Expert.

 

Not applicable for semiannual reports.
 

Item 4. Principal Accountant Fees and Services.

 

Not applicable for semiannual reports.
 

Item 5. Audit Committee of Listed Registrants.

 

Not applicable for semiannual reports.
 

Item 6.

 

(a) Refer to Item 1.

 

(b) Not applicable.

 

Item 7. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies.

 

Not applicable.
 

Item 8. Portfolio Managers of Closed-End Management Investment Companies

 

Applicable only to annual reports filed by closed-end funds.
 

Item 9. Closed-End Fund Repurchases

 

Applicable to reports filed by closed-end funds.
 

Item 10. Submission of Matters to a Vote of Security Holders

 

There have been no material changes to the procedures by which shareholders may recommend nominee to the Fund’s Board of Trustees since the Fund last provided disclosure in response to this item.

 

Item 11. Controls and Procedures

 

(a) The registrant’s principal executive officer and principal financial officer have concluded that the registrant’s disclosure controls and procedures are sufficient to ensure that information required to be disclosed by the registrant in this Form N-CSR was recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission's rules and forms, based upon such officers' evaluation of these controls and procedures as of a date within 90 days of the filing date of the report.

 

(b) There were no changes in the registrant's internal control over financial reporting that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting.

 

 

 

 

Item 12. Disclosure of Securities Lending Activities for Closed-End Management Investment Companies.

 

Not Applicable
 

Item 13. Exhibits

 

(a) Code of Ethics – Not applicable for semiannual reports.

 

(b) A separate certification for each principal executive officer and principal financial officer of the registrant as part of EX-99.CERT.

 

(c) Section 906 Certification

 

 

 

 

SIGNATURES

 

 Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

 

Morgan Stanley Mortgage Securities Trust  
   
/s/ John H. Gernon  
John H. Gernon  
Principal Executive Officer  
June 20, 2024  

 

 Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

 

/s/ John H. Gernon  
John H. Gernon  
Principal Executive Officer  
June 20, 2024  
   
/s/ Francis J. Smith  
Francis J. Smith  
Principal Financial Officer  
June 20, 2024