VMIDX vs. ATGAX

Last updated Jun 4, 2026

VMIDX (VALIC Company I Mid Cap Index Fund) and ATGAX (Aquila Opportunity Growth Fund) are both Mid Cap Blend Equities funds. A 0.50 correlation means they provide meaningful diversification when combined. VMIDX charges 0.34%/yr vs 1.50%/yr for ATGAX.

Performance

VMIDX vs. ATGAX - Performance Comparison

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

Returns By Period

VMIDX

• 1D: 0.85%
• 1M: 3.91%
• YTD: 13.87%
• 6M: 14.09%
• 1Y: 25.02%
• 3Y*: 10.35%
• 5Y*: 4.92%
• 10Y*: 8.71%

ATGAX

• 1D: 1.15%
• 1M: —
• YTD: —
• 6M: —
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

VMIDX vs. ATGAX - Yearly Performance Comparison

	2026 (YTD)
VMIDX VALIC Company I Mid Cap Index Fund	0.97%
ATGAX Aquila Opportunity Growth Fund	2.03%

Correlation

The correlation between VMIDX and ATGAX is 0.50, 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 29, 2026	0.50

Return for Risk

VMIDX vs. ATGAX — Risk / Return Rank

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

VMIDX

VMIDX Risk / Return Rank: 44
VMIDX Sharpe Ratio Rank: 36
VMIDX Sortino Ratio Rank: 37
VMIDX Omega Ratio Rank: 34
VMIDX Calmar Ratio Rank: 60
VMIDX Martin Ratio Rank: 54

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.

VMIDX vs. ATGAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for VALIC Company I Mid Cap Index Fund (VMIDX) and Aquila Opportunity Growth Fund (ATGAX). 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.

	VMIDX	ATGAX	Difference
Sharpe ratio: Return per unit of total volatility	1.75	—	—
Sortino ratio: Return per unit of downside risk	2.55	—	—
Omega ratio: Gain probability vs. loss probability	1.31	—	—
Calmar ratio: Return relative to maximum drawdown	2.98	—	—
Martin ratio: Return relative to average drawdown	10.94	—	—
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

Sharpe Ratios by Period

	VMIDX	ATGAX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.75	—	—
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.23	—	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.40	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.18	58.33	-58.15

Drawdowns

VMIDX vs. ATGAX - Drawdown Comparison

The maximum VMIDX drawdown since its inception was -67.05%, which is greater than ATGAX's maximum drawdown of 0.00%. Use the drawdown chart below to compare losses from any high point for VMIDX and ATGAX.

Drawdown Indicators

	VMIDX	ATGAX	Difference
Max Drawdown Largest peak-to-trough decline	-67.05%	0.00%	-67.05%
Max Drawdown (1Y) Largest decline over 1 year	-8.99%	—	—
Max Drawdown (3Y) Largest decline over 3 years	-34.16%	—	—
Max Drawdown (5Y) Largest decline over 5 years	-34.16%	—	—
Max Drawdown (10Y) Largest decline over 10 years	-41.76%	—	—
Current Drawdown Current decline from peak	-2.47%	0.00%	-2.47%
Average Drawdown Average peak-to-trough decline	-16.97%	0.00%	-16.97%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.44%	—	—

Volatility

Volatility by Period

	VMIDX	ATGAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.46%	—	—
Volatility (6M) Calculated over the trailing 6-month period	11.13%	—	—
Volatility (1Y) Calculated over the trailing 1-year period	15.37%	9.26%	+6.11%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	21.08%	9.26%	+11.82%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.82%	9.26%	+12.56%

VMIDX vs. ATGAX - Expense Ratio Comparison

VMIDX has a 0.34% expense ratio, which is lower than ATGAX's 1.50% expense ratio.

Dividends

VMIDX vs. ATGAX - Dividend Comparison

VMIDX's dividend yield for the trailing twelve months is around 12.50%, while ATGAX has not paid dividends to shareholders.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017
ATGAX Aquila Opportunity Growth Fund	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%
VMIDX VALIC Company I Mid Cap Index Fund	12.50%	0.00%	5.05%	13.91%	10.75%	3.62%	8.68%	11.05%	1.31%	9.01%

Frequently Asked Questions

Can I hold both VMIDX and ATGAX in my portfolio?

VMIDX and ATGAX have a correlation of 0.50, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.