PMMF vs. MMK
PMMF (iShares Prime Money Market ETF) and MMK (State Street Prime Money Market ETF) are both Money Market funds. Both are actively managed. Their 0.02 correlation means their historical movements had little consistent relationship. PMMF charges 0.20%/yr vs 0.18%/yr for MMK.
Performance
PMMF vs. MMK - Performance Comparison
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Returns By Period
PMMF
- 1D
- 0.02%
- 1M
- 0.31%
- 6M
- 1.81%
- YTD
- 2.14%
- 1Y
- 3.89%
- 3Y*
- —
- 5Y*
- —
- 10Y*
- —
- ALL TIME*
- 3.98%
MMK
- 1D
- 0.01%
- 1M
- 0.30%
- 6M
- —
- YTD
- —
- 1Y
- —
- 3Y*
- —
- 5Y*
- —
- 10Y*
- —
- ALL TIME*
- —
Liquidity Comparison
| Position | Avg. Volume Value (2W) | Avg. Volume Value (1M) | Avg. Volume Value (3M) |
|---|---|---|---|
| $170.80K | $216.85K | $200.64K | |
| $11.61M | $12.34M | $15.91M |
PMMF vs. MMK - Yearly Performance Comparison
| 2026 (YTD) | |
|---|---|
PMMF iShares Prime Money Market ETF | 1.71% |
MMK State Street Prime Money Market ETF | 1.71% |
Correlation
The correlation between PMMF and MMK is 0.02, meaning there was essentially no consistent relationship between their historical price movements. Each responded to its own set of market drivers.
| Correlation | |
|---|---|
Correlation (All Time) Calculated using the full available price history since Feb 12, 2026 | 0.02 |
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Return for Risk
PMMF vs. MMK — Risk / Return Rank
PMMF
MMK
Risk / return metrics aren't available yet — we need at least 12 months of trading data to calculate them.
PMMF vs. MMK - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares Prime Money Market ETF (PMMF) and State Street Prime Money Market ETF (MMK). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.
Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.
| PMMF | MMK | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | — | — | |
| Sortino ratioReturn per unit of downside risk | — | — | |
| Omega ratioGain probability vs. loss probability | 50.57 | — | — |
| Calmar ratioReturn relative to maximum drawdown | 156.87 | — | — |
| Martin ratioReturn relative to average drawdown | 1,677.66 | — | — |
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Drawdowns
PMMF vs. MMK - Drawdown Comparison
The maximum PMMF drawdown since its inception was -0.13%, which is greater than MMK's maximum drawdown of -0.01%. Use the drawdown chart below to compare losses from any high point for PMMF and MMK.
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Drawdown Indicators
| PMMF | MMK | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -0.13% | -0.01% | -0.12% |
Max Drawdown (1Y)Largest decline over 1 year | -0.02% | — | — |
Current DrawdownCurrent decline from peak | 0.00% | 0.00% | 0.00% |
Average DrawdownAverage peak-to-trough decline | 0.00% | 0.00% | 0.00% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.00% | — | — |
Volatility
PMMF vs. MMK - Volatility Comparison
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Volatility by Period
| PMMF | MMK | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 0.05% | — | — |
Volatility (6M)Calculated over the trailing 6-month period | 0.13% | — | — |
Volatility (1Y)Calculated over the trailing 1-year period | 0.19% | 0.18% | +0.01% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 0.34% | 0.18% | +0.16% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 0.34% | 0.18% | +0.16% |
PMMF vs. MMK - Expense Ratio Comparison
PMMF has a 0.20% expense ratio, which is higher than MMK's 0.18% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.
Dividends
PMMF vs. MMK - Dividend Comparison
PMMF's dividend yield for the trailing twelve months is around 3.69%, more than MMK's 1.68% yield.
| Position | TTM | 2025 |
|---|---|---|
MMK State Street Prime Money Market ETF | 1.68% | 0.00% |
PMMF iShares Prime Money Market ETF | 3.69% | 3.59% |
Frequently Asked Questions
PMMF and MMK have a correlation of 0.02, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
On fees, MMK is cheaper at 0.18% per year. The better choice depends on whether you care most about return, fees, risk, or income.
MMK is cheaper with a 0.18% expense ratio, compared with 0.20% for PMMF.
PMMF has the higher dividend yield at 3.69%, compared with 1.68% for MMK.
They also come from different issuers: BlackRock and State Street. Their fees differ too: 0.20% for PMMF and 0.18% for MMK.
Find the right allocation for PMMF and MMK
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