IIMOX vs. VMGMX

Last updated Jun 5, 2026

IIMOX (Voya MidCap Opportunities Portfolio) and VMGMX (Vanguard Mid-Cap Growth Index Fund Admiral Shares) are both Mid Cap Growth Equities funds. Over the past 10 years, IIMOX returned 11.59%/yr vs 12.17%/yr for VMGMX. Their correlation of 0.95 suggests significant overlap in exposure. IIMOX charges 0.66%/yr vs 0.07%/yr for VMGMX.

Performance

IIMOX vs. VMGMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Voya MidCap Opportunities Portfolio (IIMOX) and Vanguard Mid-Cap Growth Index Fund Admiral Shares (VMGMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, IIMOX achieves a 6.82% return, which is significantly lower than VMGMX's 8.36% return. Over the past 10 years, IIMOX has underperformed VMGMX with an annualized return of 11.59%, while VMGMX has yielded a comparatively higher 12.17% annualized return.

IIMOX

• 1D: -1.00%
• 1M: 5.50%
• YTD: 6.82%
• 6M: 4.57%
• 1Y: 6.93%
• 3Y*: 12.80%
• 5Y*: 5.94%
• 10Y*: 11.59%

VMGMX

• 1D: -0.83%
• 1M: 4.40%
• YTD: 8.36%
• 6M: 6.16%
• 1Y: 11.48%
• 3Y*: 16.24%
• 5Y*: 6.88%
• 10Y*: 12.17%

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

IIMOX vs. VMGMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
IIMOX Voya MidCap Opportunities Portfolio	6.82%	3.84%	15.91%	23.54%	-22.65%	12.05%	41.21%	29.45%	-7.44%	25.08%
VMGMX Vanguard Mid-Cap Growth Index Fund Admiral Shares	8.36%	10.69%	15.65%	23.93%	-28.84%	20.48%	34.45%	33.85%	-5.61%	21.83%

Correlation

The correlation between IIMOX and VMGMX is 0.86, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.86
Correlation (3Y) Calculated over the trailing 3-year period	0.86
Correlation (5Y) Calculated over the trailing 5-year period	0.91
Correlation (10Y) Calculated over the trailing 10-year period	0.94
Correlation (All Time) Calculated using the full available price history since Sep 28, 2011	0.95

The correlation between IIMOX and VMGMX has been stable across timeframes, ranging from 0.86 to 0.95 - a consistent structural relationship.

Return for Risk

IIMOX vs. VMGMX — Risk / Return Rank

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

IIMOX

IIMOX Risk / Return Rank: 6
IIMOX Sharpe Ratio Rank: 6
IIMOX Sortino Ratio Rank: 6
IIMOX Omega Ratio Rank: 6
IIMOX Calmar Ratio Rank: 6
IIMOX Martin Ratio Rank: 6

VMGMX

VMGMX Risk / Return Rank: 8
VMGMX Sharpe Ratio Rank: 9
VMGMX Sortino Ratio Rank: 9
VMGMX Omega Ratio Rank: 8
VMGMX Calmar Ratio Rank: 8
VMGMX Martin Ratio Rank: 8

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.

IIMOX vs. VMGMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Voya MidCap Opportunities Portfolio (IIMOX) and Vanguard Mid-Cap Growth Index Fund Admiral Shares (VMGMX). 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.

	IIMOX	VMGMX	Difference
Sharpe ratio: Return per unit of total volatility	0.43	0.72	-0.29
Sortino ratio: Return per unit of downside risk	0.75	1.11	-0.36
Omega ratio: Gain probability vs. loss probability	1.09	1.13	-0.04
Calmar ratio: Return relative to maximum drawdown	0.46	0.72	-0.26
Martin ratio: Return relative to average drawdown	1.38	2.16	-0.78
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

IIMOX vs. VMGMX - Sharpe Ratio Comparison

The current IIMOX Sharpe Ratio is 0.43, which is lower than the VMGMX Sharpe Ratio of 0.72. The chart below compares the historical Sharpe Ratios of IIMOX and VMGMX, 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

	IIMOX	VMGMX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.43	0.72	-0.29
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.26	0.32	-0.06
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.53	0.58	-0.05
Sharpe Ratio (All Time) Calculated using the full available price history	0.41	0.64	-0.24

Drawdowns

IIMOX vs. VMGMX - Drawdown Comparison

The maximum IIMOX drawdown since its inception was -49.62%, which is greater than VMGMX's maximum drawdown of -37.17%. Use the drawdown chart below to compare losses from any high point for IIMOX and VMGMX.

Drawdown Indicators

	IIMOX	VMGMX	Difference
Max Drawdown Largest peak-to-trough decline	-49.62%	-37.17%	-12.45%
Max Drawdown (1Y) Largest decline over 1 year	-17.25%	-15.95%	-1.30%
Max Drawdown (3Y) Largest decline over 3 years	-26.24%	-21.65%	-4.59%
Max Drawdown (5Y) Largest decline over 5 years	-38.63%	-37.17%	-1.46%
Max Drawdown (10Y) Largest decline over 10 years	-38.63%	-37.17%	-1.46%
Current Drawdown Current decline from peak	-1.00%	-0.83%	-0.17%
Average Drawdown Average peak-to-trough decline	-10.28%	-7.02%	-3.26%
Ulcer Index Depth and duration of drawdowns from previous peaks	5.53%	5.31%	+0.22%

Volatility

IIMOX vs. VMGMX - Volatility Comparison

Voya MidCap Opportunities Portfolio (IIMOX) and Vanguard Mid-Cap Growth Index Fund Admiral Shares (VMGMX) have volatilities of 4.33% and 4.42%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	IIMOX	VMGMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.33%	4.42%	-0.09%
Volatility (6M) Calculated over the trailing 6-month period	14.23%	12.46%	+1.77%
Volatility (1Y) Calculated over the trailing 1-year period	18.30%	15.92%	+2.38%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	23.22%	21.42%	+1.80%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.06%	20.99%	+1.07%

IIMOX vs. VMGMX - Expense Ratio Comparison

IIMOX has a 0.66% expense ratio, which is higher than VMGMX's 0.07% expense ratio.

Dividends

IIMOX vs. VMGMX - Dividend Comparison

IIMOX's dividend yield for the trailing twelve months is around 9.83%, more than VMGMX's 0.61% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IIMOX Voya MidCap Opportunities Portfolio	9.83%	10.50%	0.00%	0.00%	216.56%	14.45%	4.43%	12.33%	12.00%	5.41%	11.65%	17.54%
VMGMX Vanguard Mid-Cap Growth Index Fund Admiral Shares	0.61%	0.64%	0.67%	0.71%	0.78%	0.34%	0.56%	0.78%	0.84%	0.72%	0.81%	0.82%

Frequently Asked Questions

Can I hold both IIMOX and VMGMX in my portfolio?

IIMOX and VMGMX have a correlation of 0.86, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, IIMOX or VMGMX?

VMGMX has higher volatility (4.42%) compared to IIMOX (4.33%). In terms of maximum drawdown, IIMOX dropped -49.62% vs VMGMX's -37.17%.

Which has better risk-adjusted returns?

VMGMX currently has the higher Sharpe Ratio (0.72 vs 0.43), 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.