PMMF vs. GMMF

Last updated Aug 4, 2026

PMMF (iShares Prime Money Market ETF) and GMMF (iShares Government Money Market ETF) are both Money Market funds. Both are actively managed. Over the past year, PMMF returned 3.89% vs 3.73% for GMMF. Their 0.47 correlation means their historical movements had little consistent relationship. Both charge a 0.20% expense ratio.

Performance

PMMF vs. GMMF - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares Prime Money Market ETF (PMMF) and iShares Government Money Market ETF (GMMF). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both stocks are quite close, with PMMF having a 2.14% return and GMMF slightly lower at 2.05%.

PMMF

• 1D: 0.02%
• 1M: 0.31%
• 6M: 1.81%
• YTD: 2.14%
• 1Y: 3.89%
• 3Y*: —
• 5Y*: —
• 10Y*: —
• ALL TIME*: 3.98%

GMMF

• 1D: 0.01%
• 1M: 0.29%
• 6M: 1.72%
• YTD: 2.05%
• 1Y: 3.73%
• 3Y*: —
• 5Y*: —
• 10Y*: —
• ALL TIME*: 3.88%

*Multi-year figures are annualized to reflect compound growth (CAGR)

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
GMMF iShares Government Money Market ETF	$1.78M	$2.09M	$3.24M
PMMF iShares Prime Money Market ETF	$11.61M	$12.34M	$15.91M

PMMF vs. GMMF - Yearly Performance Comparison

	2026 (YTD)	2025
PMMF iShares Prime Money Market ETF	2.14%	3.75%
GMMF iShares Government Money Market ETF	2.05%	3.70%

Correlation

The correlation between PMMF and GMMF is 0.52, which is moderate. They have sometimes moved together and sometimes differently, sharing some price drivers without tracking each other closely.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.52
Correlation (All Time) Calculated using the full available price history since Feb 6, 2025	0.47

The correlation between PMMF and GMMF has been stable across timeframes, ranging from 0.47 to 0.52 - a consistent structural relationship.

Return for Risk

PMMF vs. GMMF — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

PMMF

PMMF Risk / Return Rank: 100
PMMF Sharpe Ratio Rank: 100
PMMF Sortino Ratio Rank: 100
PMMF Omega Ratio Rank: 100
PMMF Calmar Ratio Rank: 100
PMMF Martin Ratio Rank: 100

GMMF

GMMF Risk / Return Rank: 100
GMMF Sharpe Ratio Rank: 100
GMMF Sortino Ratio Rank: 100
GMMF Omega Ratio Rank: 100
GMMF Calmar Ratio Rank: 100
GMMF Martin Ratio Rank: 100

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

PMMF vs. GMMF - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Prime Money Market ETF (PMMF) and iShares Government Money Market ETF (GMMF). 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	GMMF	Difference
Sharpe ratio: Return per unit of total volatility	21.01	18.78	+2.23
Sortino ratio: Return per unit of downside risk	107.68	138.68	-30.99
Omega ratio: Gain probability vs. loss probability	50.57	40.34	+10.23
Calmar ratio: Return relative to maximum drawdown	156.87	250.39	-93.52
Martin ratio: Return relative to average drawdown	1,677.66	2,203.33	-525.66

PMMF vs. GMMF - Sharpe Ratio Comparison

The current PMMF Sharpe Ratio is 21.01, which is comparable to the GMMF Sharpe Ratio of 18.78. The chart below compares the historical Sharpe Ratios of PMMF and GMMF, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

PMMF vs. GMMF - Drawdown Comparison

The maximum PMMF drawdown since its inception was -0.13%, which is greater than GMMF's maximum drawdown of -0.03%. Use the drawdown chart below to compare losses from any high point for PMMF and GMMF.

Drawdown Indicators

	PMMF	GMMF	Difference
Max Drawdown Largest peak-to-trough decline	-0.13%	-0.03%	-0.10%
Max Drawdown (1Y) Largest decline over 1 year	-0.02%	-0.01%	-0.01%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	0.00%	0.00%	0.00%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.00%	0.00%	0.00%

Volatility

PMMF vs. GMMF - Volatility Comparison

iShares Prime Money Market ETF (PMMF) and iShares Government Money Market ETF (GMMF) have volatilities of 0.05% and 0.05%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PMMF	GMMF	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.05%	0.05%	0.00%
Volatility (6M) Calculated over the trailing 6-month period	0.13%	0.13%	0.00%
Volatility (1Y) Calculated over the trailing 1-year period	0.19%	0.20%	-0.01%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	0.34%	0.24%	+0.10%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	0.34%	0.24%	+0.10%

PMMF vs. GMMF - Expense Ratio Comparison

Both PMMF and GMMF have an expense ratio of 0.20%, making them cost-effective options compared to the broader market, where average expense ratios typically range from 0.3% to 0.9%.

Dividends

PMMF vs. GMMF - Dividend Comparison

PMMF's dividend yield for the trailing twelve months is around 3.69%, more than GMMF's 3.54% yield.

Position	TTM	2025
GMMF iShares Government Money Market ETF	3.54%	3.45%
PMMF iShares Prime Money Market ETF	3.69%	3.59%

Frequently Asked Questions

Can I hold both PMMF and GMMF in my portfolio?

PMMF and GMMF have a correlation of 0.52, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, PMMF or GMMF?

GMMF has higher volatility (0.05%) compared to PMMF (0.05%). In terms of maximum drawdown, PMMF dropped -0.13% vs GMMF's -0.03%.

Which ETF is better, PMMF or GMMF?

On 1-year performance, PMMF leads with 3.89% vs 3.73% for GMMF. Both ETFs have the same 0.20% expense ratio. Their volatility is very similar. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, PMMF or GMMF?

Over the 1-year period, PMMF has performed better with a 3.89% return vs 3.73%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, PMMF or GMMF?

PMMF and GMMF have the same expense ratio: 0.20% per year.

Which ETF pays a higher dividend yield, PMMF or GMMF?

PMMF has the higher dividend yield at 3.69%, compared with 3.54% for GMMF.

What is the main difference between PMMF and GMMF?

They also come from different issuers: BlackRock and iShares.

Which has better risk-adjusted returns?

PMMF currently has the higher Sharpe Ratio (21.01 vs 18.78), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.