MMK vs. SPYM

Last updated Jul 4, 2026

MMK (State Street Prime Money Market ETF) and SPYM (State Street SPDR Portfolio S&P 500 ETF) are both exchange-traded funds - MMK is a Money Market fund actively managed by State Street, while SPYM is a S&P 500 fund tracking the S&P 500 Index. MMK is actively managed, while SPYM is passively managed. At a correlation of -0.07, they often move in opposite directions. MMK charges 0.18%/yr vs 0.02%/yr for SPYM.

Performance

MMK vs. SPYM - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in State Street Prime Money Market ETF (MMK) and State Street SPDR Portfolio S&P 500 ETF (SPYM). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

MMK

• 1D: 0.03%
• 1M: 0.31%
• 6M: —
• YTD: —
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

SPYM

• 1D: -0.11%
• 1M: -1.01%
• 6M: 9.63%
• YTD: 9.86%
• 1Y: 20.51%
• 3Y*: 20.40%
• 5Y*: 13.02%
• 10Y*: 15.45%

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

MMK vs. SPYM - Yearly Performance Comparison

	2026 (YTD)
MMK State Street Prime Money Market ETF	1.41%
SPYM State Street SPDR Portfolio S&P 500 ETF	8.24%

Correlation

The correlation between MMK and SPYM is -0.07, meaning there is essentially no relationship between their price movements. Each responds to its own set of market drivers, making them strong candidates for combining in a diversified portfolio.

	Correlation
Correlation (All Time) Calculated using the full available price history since Feb 12, 2026	-0.07

Return for Risk

MMK vs. SPYM — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

MMK

Risk / return metrics aren't available yet — we need at least 12 months of trading data to calculate them.

SPYM

SPYM Risk / Return Rank: 64
SPYM Sharpe Ratio Rank: 64
SPYM Sortino Ratio Rank: 61
SPYM Omega Ratio Rank: 63
SPYM Calmar Ratio Rank: 59
SPYM Martin Ratio Rank: 71

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

MMK vs. SPYM - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for State Street Prime Money Market ETF (MMK) and State Street SPDR Portfolio S&P 500 ETF (SPYM). 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.

	MMK	SPYM	Difference
Sharpe ratio: Return per unit of total volatility	—	1.73	—
Sortino ratio: Return per unit of downside risk	—	2.39	—
Omega ratio: Gain probability vs. loss probability	—	1.31	—
Calmar ratio: Return relative to maximum drawdown	—	2.43	—
Martin ratio: Return relative to average drawdown	—	10.61	—

Drawdowns

MMK vs. SPYM - Drawdown Comparison

The maximum MMK drawdown since its inception was -0.01%, smaller than the maximum SPYM drawdown of -54.46%. Use the drawdown chart below to compare losses from any high point for MMK and SPYM.

Drawdown Indicators

	MMK	SPYM	Difference
Max Drawdown Largest peak-to-trough decline	-0.01%	-54.46%	+54.45%
Max Drawdown (1Y) Largest decline over 1 year	—	-8.90%	—
Max Drawdown (3Y) Largest decline over 3 years	—	-18.72%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-24.48%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-33.87%	—
Current Drawdown Current decline from peak	0.00%	-1.66%	+1.66%
Average Drawdown Average peak-to-trough decline	-0.00%	-7.13%	+7.13%
Ulcer Index Depth and duration of drawdowns from previous peaks	—	2.03%	—

Volatility

Volatility by Period

	MMK	SPYM	Difference
Volatility (1M) Calculated over the trailing 1-month period	—	5.11%	—
Volatility (6M) Calculated over the trailing 6-month period	—	9.94%	—
Volatility (1Y) Calculated over the trailing 1-year period	0.18%	12.50%	-12.32%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	0.18%	16.92%	-16.74%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	0.18%	18.00%	-17.82%

MMK vs. SPYM - Expense Ratio Comparison

MMK has a 0.18% expense ratio, which is higher than SPYM's 0.02% 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

MMK vs. SPYM - Dividend Comparison

MMK's dividend yield for the trailing twelve months is around 1.38%, more than SPYM's 1.04% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MMK State Street Prime Money Market ETF	1.38%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%
SPYM State Street SPDR Portfolio S&P 500 ETF	1.04%	1.13%	1.28%	1.44%	1.69%	1.25%	1.54%	1.79%	2.23%	1.75%	1.97%	1.98%

Frequently Asked Questions

Can I hold both MMK and SPYM in my portfolio?

MMK and SPYM have a correlation of -0.07, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which ETF is better, MMK or SPYM?

On fees, SPYM is cheaper at 0.02% per year. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF is cheaper, MMK or SPYM?

SPYM is cheaper with a 0.02% expense ratio, compared with 0.18% for MMK.

Which ETF pays a higher dividend yield, MMK or SPYM?

MMK has the higher dividend yield at 1.38%, compared with 1.04% for SPYM.

What is the main difference between MMK and SPYM?

MMK is categorized as Money Market, while SPYM is S&P 500. Their fees differ too: 0.18% for MMK and 0.02% for SPYM.