- What does MMK invest in?
- MMK seeks to maximize current income while maintaining capital preservation and liquidity by broadly investing in money market instruments. The actively managed fund employs its credit research team to assess the relative attractiveness of instruments based on the general interest rates and market supply/demand imbalances. The fund invests in US government securities (T-bills, notes, and bonds), USD-denominated certificates of deposit and time deposits from banks, US and non-US commercial paper, high-quality company obligations, asset-backed and mortgage-related securities, and repurchase agreements. The fund invests in low-risk, high-quality debt with maturities of 397 days or less, targeting a dollar-weighted average maturity of no more than 60 days and a dollar-weighted average life of 120 days or less. The fund typically invests over 25% in bank obligations. As share price and NAV are expected to fluctuate, shares may be worth more or less than their original price when sold.
- What is the expense ratio of MMK?
- State Street Prime Money Market ETF (MMK) charges an expense ratio of 0.18%. This is the annual fee deducted from fund assets to cover management and operations.
- How big is MMK?
- State Street Prime Money Market ETF (MMK) manages $29.1M in total assets. AUM determines bid-ask liquidity and the fund's vulnerability to closure — funds below ~$50M are at higher risk of liquidation.
- Is MMK actively managed or an index fund?
- MMK is actively managed — the manager selects holdings rather than tracking an index. Active funds typically charge higher expense ratios than index funds (MMK's is 0.18%) in exchange for the discretion to over- or under-weight positions.
- When was MMK launched?
- State Street Prime Money Market ETF (MMK) launched in February 2026 and is managed by SPDR.
- How has MMK performed?
- MMK's total return — price change plus reinvested distributions — is charted at the top of this page. Switch the price chart to Total Return and pick a 1-year, 3-year, 5-year, or 10-year window to read the compound annual growth rate (CAGR) over each horizon.
