ETF Evaluator: State Street Prime Money Market ETF () Follow This ETF

State Street Prime Money Market ETF Overview

State Street Prime Money Market ETF (MMK) is an actively managed Money Market Prime Money Market exchange-traded fund (ETF). State Street Investment Management launched the ETF in 2026.

The investment seeks o maximize current income, to the extent consistent with the preservation of capital and liquidity. Under normal market conditions, the Advisor intends to invest more than 25% of its total assets in bank obligations. A substantial portion of the fund may be invested in securities that are issued or traded pursuant to exemptions from registration under the federal securities laws.

About State Street Prime Money Market ETF (MMK)

There are 1 members of the management team with an average tenure of 0.47 years: Management Team (2026). Management tenure is more important for actively managed ETFs than passive index ETFs.

State Street Prime Money Market ETF has 76 securities in its portfolio. The top 10 holdings constitute 31.2% of the ETF’s assets. The ETF meets the SEC requirement of being classified as a diversified fund. The ETF is not considered to have an ESG focus with its investment selection and management.

State Street Prime Money Market ETF is part of the Capital Preservation global asset class and is within the Money Market ETF group. State Street Prime Money Market ETF has 0.0% of its portfolio invested in foreign issues. The overall assets allocated to domestic stock is 0.0% There is 0.0% allocated to foreign stock, and 0.0% is allocated to preferred stocks. The bond allocation as a percentage of total assets is 3.3% (3.3% domestic bond, 0.0% foreign bond and 0.0% convertible bond). State Street Prime Money Market ETF has 96.7% of the portfolio in cash.

Assets Under Management

The fund has $28 million in total assets, which is below the $346 million average for the Prime Money Market category. Normally, lower assets under management translates to higher average expense ratios, and greater total assets are desired. However, for some investment categories, such as small-cap investing, it may be difficult for the manager to fully employ the desired active strategy if assets grow too large or too quickly.

MMK Performance and Fees

The expense ratio measures how much of a fund’s assets are used for administrative expenses and operating expenses, including adviser fees and fees for the transfer agent and custodial services. The State Street Prime Money Market ETF expense ratio is low compared to funds in the Prime Money Market category. State Street Prime Money Market ETF has an expense ratio of 0.18%, which is 5% lower than its category average, making the fund expense ratio grade a A. While it is difficult to predict returns, it is known that high annual expense ratios reduce your rate of return, and excessive fees are difficult to overcome. Active management normally comes with higher expense ratios than passive index management. Certain investment categories such as small company and foreign also normally have higher expense ratios. It is best to compare fund expense ratios against the category averages for meaningful assessments.

High portfolio turnover can translate to higher expenses and lower aftertax returns. State Street Prime Money Market ETF has a portfolio turnover rate of 0%, which indicates that it holds its assets around /years. By way of comparison, the average portfolio turnover is for the Prime Money Market category.

Recently, in the month of July 2026, State Street Prime Money Market ETF returned 0.4%, which earned it a grade of A, as the Prime Money Market category had an average return of 0.3%. The letter grades of A, B, C, D and F are based upon relative rankings within the investment category. A grade of A, for example, would indicate that the return is in the highest 20% for that time period compared to all ETFs in that category.

State Street Prime Money Market ETF has a trailing yield of 0.00%, which is below the 3.99% category average. The fund normally distributes its income monthly and its capital gains annually.

It’s natural to seek the best-performing investments, but you must consider the relationship between risk and return and the impact of costs and taxes on your realized returns.

For more ETF grades, analysis and screening tools to help your investment discovery, join AAII for a $2, full-access trial. Learn more here: https://invest.aaii.com/membership.

Otherwise, for more information about State Street Prime Money Market ETF, including its riskiness, submit your email to unlock the rest of the article.