Filed pursuant to Rule 497(e)

File Nos. 333-237048 and 811-23556

IMPORTANT NOTICE REGARDING CHANGE IN

INVESTMENT POLICY

DATUM ONE SERIES TRUST

BRANDES SMALL CAP VALUE FUND

(the “Fund”)

Supplement dated August 30, 2024

to the Prospectus dated August 5, 2024

Effective, October 29, 2024 the Fund’s principal investment strategies will be revised to reflect a change regarding how the Fund determines a company to be a small capitalization company, including to revise the Fund’s 80% policy pursuant to Rule 35d-1 under the Investment Company Act of 1940. The revised policy will state that under normal market conditions, the Fund will invest at least 80% of its net assets measured at the time of purchase in securities of companies with small market capitalizations. The Fund considers a company to be a small capitalization company if it has a market capitalization of $7.5 billion or less at the time of purchase.

The subsection entitled “Principal Investments Strategies” of the Fund’s “Summary Section” will be deleted and restated in its entirety as follows:

The Small Cap Value Fund invests primarily in equity securities of U.S. companies with small market capitalizations (market value of publicly traded equity securities). Equity securities include common and preferred stocks, warrants and rights. Under normal market conditions, the Fund will invest at least 80% of its net assets measured at the time of purchase in securities of companies with small market capitalizations. The Fund considers a company to be a small capitalization company if it has a market capitalization of $7.5 billion or less at the time of purchase. The Fund may invest up to 10% of its total assets, measured at the time of purchase, in corporate fixed-income securities. The Fund may invest up to 10% of its total assets, measured at the time of purchase, in securities of companies located outside of the United States. However, the combined total assets invested in fixed-income securities and in securities of companies located outside of the United States may not exceed 15%, measured at the time of purchase. The Fund may invest up to 5% of its total assets, measured at the time of purchase, in any one company. From time to time, the Fund may invest more than 20% of its assets in any market sector, such as the industrials sector or health care sector.

The Small Cap Value Fund may invest from time to time in cash or short-term cash equivalent securities either as part of its overall investment strategy or for temporary defensive purposes in response to adverse market, economic, political or other conditions. The amount of such holdings will vary and will depend on the Adviser’s assessment of the quantity and quality of investment opportunities that exist at any given time, and may at times be relatively high.

Brandes Investment Partners, L.P., the investment adviser (the “Adviser”), uses the principles of value investing to analyze and select securities for the Small Cap Value Fund’s investment portfolio. When buying securities, the Adviser assesses the estimated “intrinsic” value of a company based on data such as a company’s earnings, cash flow generation, and/or asset value of the underlying business. By choosing securities that are selling at a discount to the Adviser’s estimates of the underlying company’s intrinsic value, the Adviser seeks to establish an opportunity for long-term capital appreciation. The Adviser may sell a security when its price reaches the Adviser’s estimate of the underlying company’s intrinsic value, the Adviser believes that other investments are more attractive, or for other reasons.

Additionally, the subsection “Investment Policies” of the “Investment Objective, Policies, and Risks” section related to the Fund will be deleted and restated in its entirety as follows:

Small Cap Value Fund

The Small Cap Value Fund invests primarily in equity securities of U.S. companies with small market capitalizations (market value of publicly traded equity securities). Equity securities include common and preferred stocks, warrants and rights. Under normal market conditions, the Fund will invest at least 80% of its net assets measured at the time of purchase in securities of companies with small market capitalizations. The Fund currently considers a company to be a small capitalization company if it has a market capitalization of $7.5 billion or less at the time of purchase. The Fund may invest up to 10% of its total assets, measured at the time of purchase, in corporate fixed-income securities. The Fund may invest up to 10% of its total assets, measured at the time of purchase, in securities of companies located outside of the United States. However, the combined total assets invested in fixed-income securities and in securities of companies located outside of the United States may not exceed 15%, measured at the time of purchase. The Fund may invest up to 5% of its total assets, measured at the time of purchase, in any one company. From time to time, the Fund may invest more than 20% of its assets in any market sector, such as the industrials sector or health care sector.

This Supplement and the Prospectus and Statement of Additional Information should be retained for future reference.