IIRMX vs. VYMSX

Last updated Jun 25, 2026

IIRMX (Voya Russell Mid Cap Index Portfolio) and VYMSX (Voya Mid Cap Research Enhanced Index Fund) are both Mid Cap Blend Equities funds from Voya. Over the past 10 years, IIRMX returned 11.92%/yr vs 10.93%/yr for VYMSX. With a 0.96 correlation, they move nearly in lockstep. IIRMX charges 0.40%/yr vs 0.82%/yr for VYMSX.

Performance

IIRMX vs. VYMSX - Performance Comparison

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

Returns By Period

The year-to-date returns for both stocks are quite close, with IIRMX having a 16.85% return and VYMSX slightly lower at 16.77%. Over the past 10 years, IIRMX has outperformed VYMSX with an annualized return of 11.92%, while VYMSX has yielded a comparatively lower 10.93% annualized return.

IIRMX

• 1D: -1.22%
• 1M: 2.06%
• YTD: 16.85%
• 6M: 14.98%
• 1Y: 23.94%
• 3Y*: 18.20%
• 5Y*: 8.52%
• 10Y*: 11.92%

VYMSX

• 1D: -1.58%
• 1M: 3.71%
• YTD: 16.77%
• 6M: 14.35%
• 1Y: 25.15%
• 3Y*: 17.08%
• 5Y*: 8.97%
• 10Y*: 10.93%

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

IIRMX vs. VYMSX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
IIRMX Voya Russell Mid Cap Index Portfolio	16.85%	10.40%	14.78%	16.74%	-17.55%	21.79%	16.04%	29.16%	-9.30%	18.05%
VYMSX Voya Mid Cap Research Enhanced Index Fund	16.77%	6.79%	14.92%	17.35%	-14.63%	27.47%	8.26%	28.18%	-14.55%	13.43%

Correlation

The correlation between IIRMX and VYMSX is 0.95 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.95
Correlation (3Y) Calculated over the trailing 3-year period	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.95
Correlation (10Y) Calculated over the trailing 10-year period	0.95
Correlation (All Time) Calculated using the full available price history since Mar 11, 2008	0.96

The correlation between IIRMX and VYMSX has been stable across timeframes, ranging from 0.94 to 0.96 - a consistent structural relationship.

Return for Risk

IIRMX vs. VYMSX — Risk / Return Rank

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

IIRMX

IIRMX Risk / Return Rank: 51
IIRMX Sharpe Ratio Rank: 27
IIRMX Sortino Ratio Rank: 32
IIRMX Omega Ratio Rank: 46
IIRMX Calmar Ratio Rank: 72
IIRMX Martin Ratio Rank: 76

VYMSX

VYMSX Risk / Return Rank: 48
VYMSX Sharpe Ratio Rank: 40
VYMSX Sortino Ratio Rank: 41
VYMSX Omega Ratio Rank: 35
VYMSX Calmar Ratio Rank: 65
VYMSX Martin Ratio Rank: 62

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.

IIRMX vs. VYMSX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Voya Russell Mid Cap Index Portfolio (IIRMX) 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.

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.

	IIRMX	VYMSX	Difference
Sharpe ratio: Return per unit of total volatility	1.25	1.66	-0.41
Sortino ratio: Return per unit of downside risk	2.02	2.38	-0.36
Omega ratio: Gain probability vs. loss probability	1.32	1.28	+0.04
Calmar ratio: Return relative to maximum drawdown	2.94	2.84	+0.10
Martin ratio: Return relative to average drawdown	12.58	11.04	+1.54

IIRMX vs. VYMSX - Sharpe Ratio Comparison

The current IIRMX Sharpe Ratio is 1.25, which is comparable to the VYMSX Sharpe Ratio of 1.66. The chart below compares the historical Sharpe Ratios of IIRMX 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.

Drawdowns

IIRMX vs. VYMSX - Drawdown Comparison

The maximum IIRMX drawdown since its inception was -56.44%, roughly equal to the maximum VYMSX drawdown of -57.85%. Use the drawdown chart below to compare losses from any high point for IIRMX and VYMSX.

Drawdown Indicators

	IIRMX	VYMSX	Difference
Max Drawdown Largest peak-to-trough decline	-56.44%	-57.85%	+1.41%
Max Drawdown (1Y) Largest decline over 1 year	-9.61%	-10.34%	+0.73%
Max Drawdown (3Y) Largest decline over 3 years	-21.18%	-24.02%	+2.84%
Max Drawdown (5Y) Largest decline over 5 years	-26.26%	-31.71%	+5.45%
Max Drawdown (10Y) Largest decline over 10 years	-40.41%	-43.69%	+3.28%
Current Drawdown Current decline from peak	-1.43%	-1.58%	+0.15%
Average Drawdown Average peak-to-trough decline	-7.86%	-9.15%	+1.29%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.18%	2.60%	-0.42%

Volatility

IIRMX vs. VYMSX - Volatility Comparison

The current volatility for Voya Russell Mid Cap Index Portfolio (IIRMX) is 4.69%, while Voya Mid Cap Research Enhanced Index Fund (VYMSX) has a volatility of 6.11%. This indicates that IIRMX 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

	IIRMX	VYMSX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.69%	6.11%	-1.42%
Volatility (6M) Calculated over the trailing 6-month period	19.53%	13.23%	+6.30%
Volatility (1Y) Calculated over the trailing 1-year period	22.58%	17.75%	+4.83%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	20.40%	23.41%	-3.01%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	20.38%	22.93%	-2.55%

IIRMX vs. VYMSX - Expense Ratio Comparison

IIRMX has a 0.40% expense ratio, which is lower than VYMSX's 0.82% expense ratio.

Dividends

IIRMX vs. VYMSX - Dividend Comparison

IIRMX's dividend yield for the trailing twelve months is around 37.76%, more than VYMSX's 25.49% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IIRMX Voya Russell Mid Cap Index Portfolio	37.76%	13.19%	10.43%	11.78%	10.34%	10.34%	14.22%	20.78%	15.64%	8.09%	14.11%	10.13%
VYMSX Voya Mid Cap Research Enhanced Index Fund	25.49%	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 IIRMX and VYMSX in my portfolio?

With a correlation of 0.95, IIRMX and VYMSX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, IIRMX or VYMSX?

VYMSX has higher volatility (6.11%) compared to IIRMX (4.69%). In terms of maximum drawdown, IIRMX dropped -56.44% vs VYMSX's -57.85%.

Which has better risk-adjusted returns?

VYMSX currently has the higher Sharpe Ratio (1.66 vs 1.25), 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.