MAMEX vs. MARMX

Last updated Jun 23, 2026

MAMEX (Mutual of America Mid-Cap Equity Index Fund) and MARMX (Mutual of America Retirement Income Fund) are both mutual funds - MAMEX is a Mid Cap Blend Equities fund managed by Mutual of America, while MARMX is a Target Retirement Date fund managed by Mutual of America. Over the past 5 years, MAMEX returned 7.72%/yr vs 3.21%/yr for MARMX. A 0.73 correlation means they provide meaningful diversification when combined. MAMEX charges 0.16%/yr vs 0.13%/yr for MARMX.

Performance

MAMEX vs. MARMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Mutual of America Mid-Cap Equity Index Fund (MAMEX) and Mutual of America Retirement Income Fund (MARMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MAMEX achieves a 15.32% return, which is significantly higher than MARMX's 3.58% return.

MAMEX

• 1D: 1.13%
• 1M: 3.34%
• YTD: 15.32%
• 6M: 12.85%
• 1Y: 27.01%
• 3Y*: 14.46%
• 5Y*: 7.72%
• 10Y*: —

MARMX

• 1D: 0.50%
• 1M: 0.83%
• YTD: 3.58%
• 6M: 3.58%
• 1Y: 10.80%
• 3Y*: 7.94%
• 5Y*: 3.21%
• 10Y*: —

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

MAMEX vs. MARMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020
MAMEX Mutual of America Mid-Cap Equity Index Fund	15.32%	7.40%	13.08%	13.99%	-13.59%	23.35%	1,101.56%
MARMX Mutual of America Retirement Income Fund	3.58%	10.54%	5.88%	7.79%	-11.40%	3.49%	890.98%

Correlation

The correlation between MAMEX and MARMX is 0.79, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.79
Correlation (3Y) Calculated over the trailing 3-year period	0.75
Correlation (5Y) Calculated over the trailing 5-year period	0.74
Correlation (All Time) Calculated using the full available price history since Jun 26, 2020	0.73

The correlation between MAMEX and MARMX has been stable across timeframes, ranging from 0.73 to 0.79 - a consistent structural relationship.

Return for Risk

MAMEX vs. MARMX — Risk / Return Rank

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

MAMEX

MAMEX Risk / Return Rank: 60
MAMEX Sharpe Ratio Rank: 47
MAMEX Sortino Ratio Rank: 52
MAMEX Omega Ratio Rank: 45
MAMEX Calmar Ratio Rank: 80
MAMEX Martin Ratio Rank: 75

MARMX

MARMX Risk / Return Rank: 74
MARMX Sharpe Ratio Rank: 71
MARMX Sortino Ratio Rank: 79
MARMX Omega Ratio Rank: 73
MARMX Calmar Ratio Rank: 69
MARMX Martin Ratio Rank: 80

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.

MAMEX vs. MARMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Mutual of America Mid-Cap Equity Index Fund (MAMEX) and Mutual of America Retirement Income Fund (MARMX). 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.

	MAMEX	MARMX	Difference
Sharpe ratio: Return per unit of total volatility	1.86	2.26	-0.39
Sortino ratio: Return per unit of downside risk	2.78	3.46	-0.67
Omega ratio: Gain probability vs. loss probability	1.33	1.43	-0.10
Calmar ratio: Return relative to maximum drawdown	3.45	3.07	+0.37
Martin ratio: Return relative to average drawdown	13.16	13.77	-0.60

MAMEX vs. MARMX - Sharpe Ratio Comparison

The current MAMEX Sharpe Ratio is 1.86, which is comparable to the MARMX Sharpe Ratio of 2.26. The chart below compares the historical Sharpe Ratios of MAMEX and MARMX, 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

MAMEX vs. MARMX - Drawdown Comparison

The maximum MAMEX drawdown since its inception was -42.17%, which is greater than MARMX's maximum drawdown of -16.21%. Use the drawdown chart below to compare losses from any high point for MAMEX and MARMX.

Drawdown Indicators

	MAMEX	MARMX	Difference
Max Drawdown Largest peak-to-trough decline	-42.17%	-16.21%	-25.96%
Max Drawdown (1Y) Largest decline over 1 year	-8.84%	-3.92%	-4.92%
Max Drawdown (3Y) Largest decline over 3 years	-24.11%	-5.64%	-18.47%
Max Drawdown (5Y) Largest decline over 5 years	-24.39%	-15.94%	-8.45%
Current Drawdown Current decline from peak	-0.39%	-0.16%	-0.23%
Average Drawdown Average peak-to-trough decline	-7.44%	-4.25%	-3.19%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.29%	0.84%	+1.45%

Volatility

MAMEX vs. MARMX - Volatility Comparison

Mutual of America Mid-Cap Equity Index Fund (MAMEX) has a higher volatility of 4.67% compared to Mutual of America Retirement Income Fund (MARMX) at 2.02%. This indicates that MAMEX's price experiences larger fluctuations and is considered to be riskier than MARMX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MAMEX	MARMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.67%	2.02%	+2.65%
Volatility (6M) Calculated over the trailing 6-month period	12.35%	4.33%	+8.02%
Volatility (1Y) Calculated over the trailing 1-year period	16.35%	5.34%	+11.01%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.05%	7.56%	+14.49%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	381.65%	391.44%	-9.79%

MAMEX vs. MARMX - Expense Ratio Comparison

MAMEX has a 0.16% expense ratio, which is higher than MARMX's 0.13% 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

MAMEX vs. MARMX - Dividend Comparison

MAMEX's dividend yield for the trailing twelve months is around 10.28%, more than MARMX's 4.17% yield.

Position	TTM	2025	2024	2023	2022	2021
MAMEX Mutual of America Mid-Cap Equity Index Fund	10.28%	11.85%	9.07%	7.67%	14.01%	12.96%
MARMX Mutual of America Retirement Income Fund	4.17%	4.32%	4.16%	1.55%	5.73%	2.03%

Frequently Asked Questions

Can I hold both MAMEX and MARMX in my portfolio?

MAMEX and MARMX have a correlation of 0.79, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MAMEX or MARMX?

MAMEX has higher volatility (4.67%) compared to MARMX (2.02%). In terms of maximum drawdown, MAMEX dropped -42.17% vs MARMX's -16.21%.

Which has better risk-adjusted returns?

MARMX currently has the higher Sharpe Ratio (2.26 vs 1.86), 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.