IIMOX vs. VYMSX

Last updated Jun 4, 2026

IIMOX (Voya MidCap Opportunities Portfolio) and VYMSX (Voya Mid Cap Research Enhanced Index Fund) are both mutual funds - IIMOX is a Mid Cap Growth Equities fund managed by Voya, while VYMSX is a Mid Cap Blend Equities fund managed by Voya. Over the past 10 years, IIMOX returned 11.70%/yr vs 10.42%/yr for VYMSX. Their correlation of 0.89 suggests significant overlap in exposure. IIMOX charges 0.66%/yr vs 0.82%/yr for VYMSX.

Performance

IIMOX vs. VYMSX - Performance Comparison

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

Returns By Period

In the year-to-date period, IIMOX achieves a 7.90% return, which is significantly lower than VYMSX's 15.34% return. Over the past 10 years, IIMOX has outperformed VYMSX with an annualized return of 11.70%, while VYMSX has yielded a comparatively lower 10.42% annualized return.

IIMOX

• 1D: 0.33%
• 1M: 8.09%
• YTD: 7.90%
• 6M: 6.00%
• 1Y: 8.37%
• 3Y*: 13.18%
• 5Y*: 6.46%
• 10Y*: 11.70%

VYMSX

• 1D: 1.37%
• 1M: 5.11%
• YTD: 15.34%
• 6M: 14.36%
• 1Y: 25.10%
• 3Y*: 16.95%
• 5Y*: 8.45%
• 10Y*: 10.42%

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

IIMOX vs. VYMSX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
IIMOX Voya MidCap Opportunities Portfolio	7.90%	3.84%	15.91%	23.54%	-22.65%	12.05%	41.21%	29.45%	-7.44%	25.08%
VYMSX Voya Mid Cap Research Enhanced Index Fund	15.34%	6.79%	14.92%	17.35%	-14.63%	27.47%	8.26%	28.18%	-14.55%	13.43%

Correlation

The correlation between IIMOX and VYMSX is 0.82, 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	0.82
Correlation (3Y) Calculated over the trailing 3-year period	0.82
Correlation (5Y) Calculated over the trailing 5-year period	0.83
Correlation (10Y) Calculated over the trailing 10-year period	0.81
Correlation (All Time) Calculated using the full available price history since May 31, 2001	0.89

The correlation between IIMOX and VYMSX has been stable across timeframes, ranging from 0.81 to 0.89 - a consistent structural relationship.

Return for Risk

IIMOX vs. VYMSX — Risk / Return Rank

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

IIMOX

IIMOX Risk / Return Rank: 7
IIMOX Sharpe Ratio Rank: 7
IIMOX Sortino Ratio Rank: 7
IIMOX Omega Ratio Rank: 7
IIMOX Calmar Ratio Rank: 6
IIMOX Martin Ratio Rank: 7

VYMSX

VYMSX Risk / Return Rank: 43
VYMSX Sharpe Ratio Rank: 37
VYMSX Sortino Ratio Rank: 36
VYMSX Omega Ratio Rank: 31
VYMSX Calmar Ratio Rank: 57
VYMSX Martin Ratio Rank: 56

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. VYMSX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Voya MidCap Opportunities Portfolio (IIMOX) and Voya Mid Cap Research Enhanced Index Fund (VYMSX). 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	VYMSX	Difference
Sharpe ratio: Return per unit of total volatility	0.55	1.75	-1.19
Sortino ratio: Return per unit of downside risk	0.91	2.50	-1.59
Omega ratio: Gain probability vs. loss probability	1.10	1.29	-0.19
Calmar ratio: Return relative to maximum drawdown	0.59	2.88	-2.30
Martin ratio: Return relative to average drawdown	1.76	11.25	-9.49
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. VYMSX - Sharpe Ratio Comparison

The current IIMOX Sharpe Ratio is 0.55, which is lower than the VYMSX Sharpe Ratio of 1.75. The chart below compares the historical Sharpe Ratios of IIMOX and VYMSX, 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	VYMSX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.55	1.75	-1.19
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.28	0.37	-0.09
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.54	0.46	+0.08
Sharpe Ratio (All Time) Calculated using the full available price history	0.41	0.40	+0.01

Drawdowns

IIMOX vs. VYMSX - Drawdown Comparison

The maximum IIMOX drawdown since its inception was -49.62%, smaller than the maximum VYMSX drawdown of -57.85%. Use the drawdown chart below to compare losses from any high point for IIMOX and VYMSX.

Drawdown Indicators

	IIMOX	VYMSX	Difference
Max Drawdown Largest peak-to-trough decline	-49.62%	-57.85%	+8.23%
Max Drawdown (1Y) Largest decline over 1 year	-17.25%	-10.34%	-6.91%
Max Drawdown (3Y) Largest decline over 3 years	-26.24%	-24.02%	-2.22%
Max Drawdown (5Y) Largest decline over 5 years	-38.63%	-31.71%	-6.92%
Max Drawdown (10Y) Largest decline over 10 years	-38.63%	-43.69%	+5.06%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-10.29%	-9.16%	-1.13%
Ulcer Index Depth and duration of drawdowns from previous peaks	5.53%	2.57%	+2.96%

Volatility

IIMOX vs. VYMSX - Volatility Comparison

The current volatility for Voya MidCap Opportunities Portfolio (IIMOX) is 4.11%, while Voya Mid Cap Research Enhanced Index Fund (VYMSX) has a volatility of 4.81%. This indicates that IIMOX experiences smaller price fluctuations and is considered to be less risky than VYMSX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	IIMOX	VYMSX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.11%	4.81%	-0.70%
Volatility (6M) Calculated over the trailing 6-month period	14.21%	12.33%	+1.88%
Volatility (1Y) Calculated over the trailing 1-year period	18.29%	17.08%	+1.21%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	23.23%	23.33%	-0.10%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.07%	22.91%	-0.84%

IIMOX vs. VYMSX - Expense Ratio Comparison

IIMOX has a 0.66% expense ratio, which is lower than VYMSX's 0.82% expense ratio.

Dividends

IIMOX vs. VYMSX - Dividend Comparison

IIMOX's dividend yield for the trailing twelve months is around 9.73%, less than VYMSX's 25.81% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IIMOX Voya MidCap Opportunities Portfolio	9.73%	10.50%	0.00%	0.00%	216.56%	14.45%	4.43%	12.33%	12.00%	5.41%	11.65%	17.54%
VYMSX Voya Mid Cap Research Enhanced Index Fund	25.81%	29.77%	11.50%	0.96%	6.78%	14.81%	0.79%	2.00%	13.24%	7.58%	1.83%	6.83%

Frequently Asked Questions

Can I hold both IIMOX and VYMSX in my portfolio?

IIMOX and VYMSX have a correlation of 0.82, 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 VYMSX?

VYMSX has higher volatility (4.81%) compared to IIMOX (4.11%). In terms of maximum drawdown, IIMOX dropped -49.62% vs VYMSX's -57.85%.

Which has better risk-adjusted returns?

VYMSX currently has the higher Sharpe Ratio (1.75 vs 0.55), 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.