ATGAX vs. MAMEX

Last updated Jun 20, 2026

ATGAX (Aquila Opportunity Growth Fund) and MAMEX (Mutual of America Mid-Cap Equity Index Fund) are both Mid Cap Blend Equities funds. A 0.79 correlation means they provide meaningful diversification when combined. ATGAX charges 1.50%/yr vs 0.16%/yr for MAMEX.

Performance

ATGAX vs. MAMEX - Performance Comparison

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

Returns By Period

ATGAX

• 1D: 0.90%
• 1M: —
• YTD: —
• 6M: —
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

MAMEX

• 1D: 1.13%
• 1M: 4.23%
• YTD: 15.32%
• 6M: 14.81%
• 1Y: 27.01%
• 3Y*: 14.46%
• 5Y*: 7.72%
• 10Y*: —

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

ATGAX vs. MAMEX - Yearly Performance Comparison

	2026 (YTD)
ATGAX Aquila Opportunity Growth Fund	2.38%
MAMEX Mutual of America Mid-Cap Equity Index Fund	2.16%

Correlation

The correlation between ATGAX and MAMEX 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 (All Time) Calculated using the full available price history since May 28, 2026	0.79

Return for Risk

ATGAX vs. MAMEX — Risk / Return Rank

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

ATGAX

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

MAMEX

MAMEX Risk / Return Rank: 60
MAMEX Sharpe Ratio Rank: 48
MAMEX Sortino Ratio Rank: 53
MAMEX Omega Ratio Rank: 45
MAMEX Calmar Ratio Rank: 81
MAMEX Martin Ratio Rank: 76

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.

ATGAX vs. MAMEX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Aquila Opportunity Growth Fund (ATGAX) and Mutual of America Mid-Cap Equity Index Fund (MAMEX). 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.

	ATGAX	MAMEX	Difference
Sharpe ratio: Return per unit of total volatility	—	1.86	—
Sortino ratio: Return per unit of downside risk	—	2.78	—
Omega ratio: Gain probability vs. loss probability	—	1.33	—
Calmar ratio: Return relative to maximum drawdown	—	3.45	—
Martin ratio: Return relative to average drawdown	—	13.16	—

Drawdowns

ATGAX vs. MAMEX - Drawdown Comparison

The maximum ATGAX drawdown since its inception was -3.70%, smaller than the maximum MAMEX drawdown of -42.17%. Use the drawdown chart below to compare losses from any high point for ATGAX and MAMEX.

Drawdown Indicators

	ATGAX	MAMEX	Difference
Max Drawdown Largest peak-to-trough decline	-3.70%	-42.17%	+38.47%
Max Drawdown (1Y) Largest decline over 1 year	—	-8.84%	—
Max Drawdown (3Y) Largest decline over 3 years	—	-24.11%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-24.39%	—
Current Drawdown Current decline from peak	-0.70%	-0.39%	-0.31%
Average Drawdown Average peak-to-trough decline	-0.99%	-7.44%	+6.45%
Ulcer Index Depth and duration of drawdowns from previous peaks	—	2.29%	—

Volatility

Volatility by Period

	ATGAX	MAMEX	Difference
Volatility (1M) Calculated over the trailing 1-month period	—	4.67%	—
Volatility (6M) Calculated over the trailing 6-month period	—	12.35%	—
Volatility (1Y) Calculated over the trailing 1-year period	19.52%	16.35%	+3.17%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	19.52%	22.05%	-2.53%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.52%	381.65%	-362.13%

ATGAX vs. MAMEX - Expense Ratio Comparison

ATGAX has a 1.50% expense ratio, which is higher than MAMEX's 0.16% expense ratio.

Dividends

ATGAX vs. MAMEX - Dividend Comparison

ATGAX has not paid dividends to shareholders, while MAMEX's dividend yield for the trailing twelve months is around 10.28%.

Position	TTM	2025	2024	2023	2022	2021
ATGAX Aquila Opportunity Growth Fund	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%
MAMEX Mutual of America Mid-Cap Equity Index Fund	10.28%	11.85%	9.07%	7.67%	14.01%	12.96%

Frequently Asked Questions

Can I hold both ATGAX and MAMEX in my portfolio?

ATGAX and MAMEX 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.