MAMEX vs. FZFLX

Last updated Jun 4, 2026

MAMEX (Mutual of America Mid-Cap Equity Index Fund) and FZFLX (Fidelity SAI Small-Mid Cap 500 Index Fund) are both Mid Cap Blend Equities funds. Over the past 5 years, MAMEX returned 7.22%/yr vs 12.03%/yr for FZFLX. Their correlation of 0.85 suggests significant overlap in exposure. MAMEX charges 0.16%/yr vs 0.05%/yr for FZFLX.

Performance

MAMEX vs. FZFLX - 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 Fidelity SAI Small-Mid Cap 500 Index Fund (FZFLX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MAMEX achieves a 14.08% return, which is significantly lower than FZFLX's 33.04% return.

MAMEX

• 1D: 0.88%
• 1M: 3.94%
• YTD: 14.08%
• 6M: 14.46%
• 1Y: 25.52%
• 3Y*: 15.21%
• 5Y*: 7.22%
• 10Y*: —

FZFLX

• 1D: 1.53%
• 1M: 6.05%
• YTD: 33.04%
• 6M: 33.74%
• 1Y: 48.52%
• 3Y*: 24.40%
• 5Y*: 12.03%
• 10Y*: 14.07%

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

MAMEX vs. FZFLX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020
MAMEX Mutual of America Mid-Cap Equity Index Fund	14.08%	7.40%	13.08%	13.99%	-13.59%	23.35%	925.33%
FZFLX Fidelity SAI Small-Mid Cap 500 Index Fund	33.04%	10.76%	15.52%	17.75%	-15.62%	20.40%	19.69%

Correlation

The correlation between MAMEX and FZFLX 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	0.88
Correlation (5Y) Calculated over the trailing 5-year period	0.83
Correlation (All Time) Calculated using the full available price history since Jan 3, 2020	0.85

The correlation between MAMEX and FZFLX has been stable across timeframes, ranging from 0.79 to 0.88 - a consistent structural relationship.

Return for Risk

MAMEX vs. FZFLX — Risk / Return Rank

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

MAMEX

MAMEX Risk / Return Rank: 54
MAMEX Sharpe Ratio Rank: 42
MAMEX Sortino Ratio Rank: 45
MAMEX Omega Ratio Rank: 40
MAMEX Calmar Ratio Rank: 76
MAMEX Martin Ratio Rank: 68

FZFLX

FZFLX Risk / Return Rank: 74
FZFLX Sharpe Ratio Rank: 71
FZFLX Sortino Ratio Rank: 58
FZFLX Omega Ratio Rank: 58
FZFLX Calmar Ratio Rank: 91
FZFLX Martin Ratio Rank: 93

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. FZFLX - 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 Fidelity SAI Small-Mid Cap 500 Index Fund (FZFLX). 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.

	MAMEX	FZFLX	Difference
Sharpe ratio: Return per unit of total volatility	1.90	2.44	-0.55
Sortino ratio: Return per unit of downside risk	2.82	3.22	-0.39
Omega ratio: Gain probability vs. loss probability	1.34	1.42	-0.08
Calmar ratio: Return relative to maximum drawdown	3.45	4.77	-1.32
Martin ratio: Return relative to average drawdown	13.17	20.14	-6.97
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MAMEX vs. FZFLX - Sharpe Ratio Comparison

The current MAMEX Sharpe Ratio is 1.90, which is comparable to the FZFLX Sharpe Ratio of 2.44. The chart below compares the historical Sharpe Ratios of MAMEX and FZFLX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	MAMEX	FZFLX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.90	2.44	-0.55
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.37	0.57	-0.20
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.67	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.17	0.63	-0.46

Drawdowns

MAMEX vs. FZFLX - Drawdown Comparison

The maximum MAMEX drawdown since its inception was -42.17%, roughly equal to the maximum FZFLX drawdown of -42.03%. Use the drawdown chart below to compare losses from any high point for MAMEX and FZFLX.

Drawdown Indicators

	MAMEX	FZFLX	Difference
Max Drawdown Largest peak-to-trough decline	-42.17%	-42.03%	-0.14%
Max Drawdown (1Y) Largest decline over 1 year	-8.84%	-10.68%	+1.84%
Max Drawdown (3Y) Largest decline over 3 years	-24.11%	-22.29%	-1.82%
Max Drawdown (5Y) Largest decline over 5 years	-24.39%	-24.77%	+0.38%
Max Drawdown (10Y) Largest decline over 10 years	—	-42.03%	—
Current Drawdown Current decline from peak	0.00%	-0.33%	+0.33%
Average Drawdown Average peak-to-trough decline	-7.50%	-5.74%	-1.76%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.28%	2.52%	-0.24%

Volatility

MAMEX vs. FZFLX - Volatility Comparison

The current volatility for Mutual of America Mid-Cap Equity Index Fund (MAMEX) is 4.43%, while Fidelity SAI Small-Mid Cap 500 Index Fund (FZFLX) has a volatility of 7.41%. This indicates that MAMEX experiences smaller price fluctuations and is considered to be less risky than FZFLX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MAMEX	FZFLX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.43%	7.41%	-2.98%
Volatility (6M) Calculated over the trailing 6-month period	12.23%	17.71%	-5.48%
Volatility (1Y) Calculated over the trailing 1-year period	16.08%	20.84%	-4.76%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.01%	21.11%	+0.90%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	383.36%	21.11%	+362.25%

MAMEX vs. FZFLX - Expense Ratio Comparison

MAMEX has a 0.16% expense ratio, which is higher than FZFLX's 0.05% 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. FZFLX - Dividend Comparison

MAMEX's dividend yield for the trailing twelve months is around 10.39%, less than FZFLX's 43.42% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FZFLX Fidelity SAI Small-Mid Cap 500 Index Fund	43.42%	57.77%	10.20%	2.35%	79.79%	50.77%	7.19%	6.49%	7.69%	1.68%	0.93%	0.67%
MAMEX Mutual of America Mid-Cap Equity Index Fund	10.39%	11.85%	9.07%	7.67%	14.01%	12.96%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both MAMEX and FZFLX in my portfolio?

MAMEX and FZFLX 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 FZFLX?

FZFLX has higher volatility (7.41%) compared to MAMEX (4.43%). In terms of maximum drawdown, MAMEX dropped -42.17% vs FZFLX's -42.03%.

Which has better risk-adjusted returns?

FZFLX currently has the higher Sharpe Ratio (2.44 vs 1.90), 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.