ING Money Market Portfolio

INVESTMENT OBJECTIVE

The Portfolio seeks to provide high current return, consistent with preservation of capital and liquidity, through investment in high-quality money market instruments while maintaining a stable share price of $1.00.

FEES AND EXPENSES OF THE PORTFOLIO

The table describes the fees and expenses that you may pay if you buy and hold shares of the Portfolio. The table does not reflect fees or expenses that are, or may be, imposed under your variable annuity contracts or variable life insurance policies (“Variable Contract”) or a qualified pension or retirement plan (“Qualified Plan”). For more information on these charges, please refer to the documents governing your Variable Contract or consult your plan administrator.

The Example is intended to help you compare the cost of investing in shares of the Portfolio with the costs of investing in other mutual funds. The Example does not reflect expenses and charges which are, or may be, imposed under your Variable Contract or Qualified Plan. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated. The Example also assumes that your investment had a 5% return each year and that the Portfolio’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

The Example reflects applicable expense limitation agreements and/or waivers in effect, if any, for the one-year period and the first year of the three-, five-, and ten-year periods.

PRINCIPAL INVESTMENT STRATEGIES

The Portfolio invests in a portfolio of high-quality, U.S. dollar denominated, short-term debt securities that are determined by the sub-adviser (“Sub-Adviser”) to present minimal credit risk.

The Portfolio may maintain a rating from one or more rating agencies that provide ratings on money market funds. There can be no assurance that the Portfolio will maintain any particular rating or maintain it with a particular rating agency. To maintain a rating, the Sub-Adviser may manage the Portfolio more conservatively than if it was not rated.

Investments of the Portfolio are valued based on the amortized cost valuation method pursuant to Rule 2a-7 under the Investment Company Act of 1940 (“Rule 2a-7”). Obligations in which the Portfolio invests generally have remaining maturities of 397 days or less, although upon satisfying certain conditions of Rule 2a-7, the Portfolio may, to the extent otherwise permissible, invest

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The Portfolio will invest in obligations permitted to be purchased under Rule 2a-7 including, but not limited to: (i) U.S. government securities and obligations of its agencies or instrumentalities; (ii) commercial paper, mortgage- and asset-backed securities, repurchase agreements, guaranteed investment contracts, municipal securities, loan participation interests, and medium-term notes; (iii) other money market mutual funds; and (iv) the following domestic, Eurodollar and Yankee Dollar obligations: certificates of deposit, fixed-time deposits, bankers acceptances, and other promissory notes, including floating and variable rate obligations issued by U.S. or foreign bank holding companies and their bank subsidiaries, branches, and agencies. The Portfolio may significantly invest in securities issued by financial services companies including, among other entities, banks and bank holding companies, investment banks, trust companies, insurance companies, finance companies, and broker-dealers. The Portfolio may invest more than 25% of its assets in instruments issued by domestic banks.

The Portfolio may invest in other investment companies to the extent permitted under the Investment Company Act of 1940, as amended, and the rules, regulations, and exemptive orders thereunder (“1940 Act”).

The Portfolio may purchase securities on a when-issued basis and purchase or sell them on a forward commitment basis. The Portfolio may also invest in variable rate master demand obligations, which are unsecured demand notes that permit the underlying indebtedness to vary and provide for periodic adjustments in the interest rate.

In choosing investments for the Portfolio, the Sub-Adviser employs a highly disciplined, four-step investment process designed to ensure preservation of capital and liquidity, as well as adherence to regulatory requirements. The four steps are: first, a formal list of high-quality issuers is actively maintained; second, securities of issuers on the approved list that meet maturity guidelines and are rated first tier ( i.e ., they are given the highest short-term rating by at least two nationally recognized statistical rating organizations or by a single rating organization if a security is rated only by that organization, or are determined to be of comparable quality by the Sub-Adviser pursuant to guidelines approved by the Portfolio’s Board of Trustees) are selected for investment; third, diversification is continuously monitored to ensure that regulatory limits are not exceeded; and finally, portfolio maturity decisions are made based upon expected cash flows, income opportunities available in the market, and expectations of future interest rates.

PRINCIPAL RISKS

You could lose money on an investment in the Portfolio. Any of the following risks, among others, could affect Portfolio performance or cause the Portfolio to lose money or to underperform market averages of other funds.

Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, it is possible to lose money by investing in the Portfolio.

Bank Instruments   The Portfolio may invest in certificates of deposit, fixed-time deposits, bankers’ acceptances, and other debt and deposit-type obligations issued by banks. Although the Portfolio attempts to invest only with high-quality banking institutions, most banking institutions are dependent on other institutions to fulfill their obligations. As a result, changes in economic, regulatory, political conditions, or other events that affect the banking industry may have an adverse effect on the banking institutions in which the Portfolio invests or that serve as counterparties in transactions with the Portfolio.

Credit   Prices of bonds and other debt instruments can fall if the issuer’s actual or perceived financial health deteriorates, whether because of broad economic or issuer-specific reasons. In certain cases, the issuer could be late in paying interest or principal, or could fail to pay altogether.

Currency   To the extent that the Portfolio invests directly in foreign (non-U.S.) currencies or in securities denominated in, or that trade in, foreign (non-U.S.) currencies, it is subject to the risk that those foreign (non-U.S.) currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, that the U.S. dollar will decline in value relative to the currency being hedged.

Focused Investing   To the extent that the Portfolio invests a substantial portion of its assets in a particular industry, sector, market segment, or geographical area, its investments will be sensitive to developments in that industry, sector, market segment, or geographical area. The Portfolio assumes the risk that changing economic conditions; changing political or regulatory conditions; or natural and other disasters affecting the particular industry, sector, market segment, or geographical area in which the Portfolio focuses its investments could have a significant impact on its investment performance and could ultimately cause the Portfolio to underperform, or be more volatile than, other funds that invest more broadly.

Foreign Investments   Investing in foreign (non-U.S.) securities may result in the Portfolio experiencing more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies due to: smaller markets; differing reporting, accounting, and auditing standards; nationalization, expropriation, or confiscatory taxation; foreign currency fluctuations, currency blockage, or replacement; potential for default on sovereign debt; or political changes or diplomatic developments. Markets and economies throughout the world are becoming increasingly interconnected, and conditions or events in one market, country or region may adversely impact investments or issuers in another market, country or region.

Interest Rate   With bonds and other fixed rate debt instruments, a rise in interest rates generally causes values to fall; conversely, values generally rise as interest rates fall. The higher the credit quality of the instrument, and the longer its maturity or duration, the more sensitive it is likely to be to interest rate risk. In the

Liquidity   If a security is illiquid, the Portfolio might be unable to sell the security at a time when the Portfolio’s manager might wish to sell, and the security could have the effect of decreasing the overall level of the Portfolio’s liquidity. Further, the lack of an established secondary market may make it more difficult to value illiquid securities, which could vary from the amount the Portfolio could realize upon disposition. The Portfolio may make investments that become less liquid in response to market developments or adverse investor perception. The Portfolio could lose money if it cannot sell a security at the time and price that would be most beneficial to the Portfolio.

Mortgage- and/or Asset-Backed Securities Defaults on or the low credit quality or liquidity of the underlying assets of the asset-backed (including mortgage-backed) securities held by the Portfolio may impair the value of the securities. There may be limitations on the enforceability of any security interest granted with respect to those underlying assets. These securities also present a higher degree of prepayment and extension risk and interest rate risk than do other types of fixed-income securities.

Municipal Obligations   The municipal market in which the Portfolio invests is volatile and can be significantly affected by adverse tax, legislative, or political changes and the financial condition of the issuers of municipal securities.

Other Investment Companies - Money Market Funds The Portfolio may only invest in other investment companies that qualify as money market funds under Rule 2a-7 of the 1940 Act. The risk of investing in such money market funds is that such money market funds may not maintain a stable net asset value of $1.00 or otherwise comply with Rule 2a-7. If the Portfolio invests in other investment companies, you will pay a proportionate share of the expenses of those other investment companies (including management fees, administration fees, and custodial fees) in addition to the expenses of the Portfolio.

Prepayment and Extension   Prepayment risk is the risk that principal on mortgages or other loan obligations underlying a security may be repaid prior to the stated maturity date, which may reduce the market value of the security and the anticipated yield-to-maturity. Extension risk is the risk that an issuer will exercise its right to repay principal on an obligation held by the Portfolio later than expected, which may decrease the value of the obligation and prevent the Portfolio from investing expected repayment proceeds in securities paying yields higher than the yields paid by the securities that were expected to be repaid.

U.S. Government Securities and Obligations   U.S. government securities are obligations of, or guaranteed by, the U.S. government, its agencies or government-sponsored enterprises. U.S. government securities are subject to market and interest rate risk, and may be subject to varying degrees of credit risk.

When Issued and Delayed Delivery Securities and Forward Commitments   When issued securities, delayed delivery securities and forward commitments involve the risk that the security the Portfolio buys will lose value prior to its delivery. There also is the risk that the security will not be issued or that the other party will not meet its obligation. If this occurs, the Portfolio loses both the investment opportunity for the assets it set aside to pay for the security and any gain in the security’s price.

An investment in the Portfolio is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation, the Federal Reserve Board or any other government agency.

PERFORMANCE INFORMATION

The following information is intended to help you understand the risks of investing in the Portfolio. The following bar chart shows the changes in the Portfolio’s Class S shares’ and Class I shares’ performance from year to year, and the table compares the Portfolio’s Class S shares’ and Class I shares’ performance to the performance of a broad-based securities market index/indices for the same period. Class I shares’ performance has been adjusted to reflect the higher expenses of Class S shares. The Class S shares and Class I shares of the Portfolio would have substantially similar performance because they invest in the same portfolio of securities. However, Class I shares’ performance would be higher than Class S shares’ performance because of the higher expenses paid by Class S shares. The Portfolio’s performance information reflects applicable fee waivers and/or expense limitations in effect during the period presented. Absent such fee waivers/expense limitations, if any, performance would have been lower. Performance in the Average Annual Total Returns table does not include insurance-related charges imposed under a Variable Contract or expenses related to a Qualified Plan. If these charges or expenses were included, performance would be lower. Thus, you should not compare the Portfolio’s performance directly with the performance information of other investment products without taking into account all insurance-related charges and expenses payable under your Variable Contract or Qualified Plan. The Portfolio’s past performance is no guarantee of future results.

The bar chart below shows the Portfolio’s adjusted Class I shares’ performance (2003-2010) and Class S shares’ performance (2011- 2012).

Best quarter: 3rd, 2007, 1.29% and Worst quarter: 4th, 2010, (0.04)%

For the Portfolio’s current 7 day yield and current 7 day effective yield, when available, please call the Portfolio at 1-800-992-0180.

PORTFOLIO MANAGEMENT

PURCHASE AND SALE OF PORTFOLIO SHARES

Shares of the Portfolio are not offered directly to the public. Purchase and sale of shares may be made only by separate accounts of insurance companies serving as investment options under Variable Contracts or by Qualified Plans, custodian accounts, and certain investment advisers and their affiliates, other investment companies, or permitted investors. Please refer to the prospectus for the appropriate insurance company separate account, investment company, or your plan documents for information on how to direct investments in, or sale from, an investment option corresponding to the Portfolio and any fees that may apply. Participating insurance companies and certain other designated organizations are authorized to receive purchase orders on the Portfolio’s behalf.

TAX INFORMATION

Distributions made by the Portfolio to a Variable Contract or Qualified Plan, and exchanges and redemptions of Portfolio shares made by a Variable Contract or Qualified Plan, ordinarily do not cause the corresponding contract holder or plan participant to recognize income or gain for federal income tax purposes. See the accompanying contract prospectus or the governing documents of your Qualified Plan for information regarding the federal income tax treatment of the distributions to your Variable Contract or Qualified Plan and the holders of the contracts or plan participants.

PAYMENTS TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you invest in the Portfolio through a Variable Contract issued by an insurance company or through a Qualified Plan that, in turn, was purchased or serviced through an insurance company, broker-dealer or other financial intermediary, the Portfolio and its adviser or distributor or their affiliates may: (1) make payments to the insurance company issuer of the Variable Contract or to the company servicing the Qualified Plan; and (2) make payments to the insurance company, broker-dealer or other financial intermediary. These payments may create a conflict of interest by: (1) influencing the insurance company or the company servicing the Qualified Plan to make the Portfolio available as an investment option for the Variable Contract or the Qualified Plan; or (2) by influencing the broker-dealer or other intermediary and your salesperson to recommend the Variable Contract or the pension servicing agent and/or the Portfolio over other options. Ask your salesperson or Qualified Plan administrator or visit your financial intermediary’s website for more information.