IIRMX vs. VMCPX

Last updated Jun 3, 2026

IIRMX (Voya Russell Mid Cap Index Portfolio) and VMCPX (Vanguard Mid-Cap Index Fund Institutional Plus Shares) are both Mid Cap Blend Equities funds. Over the past 10 years, IIRMX returned 11.55%/yr vs 11.60%/yr for VMCPX. With a 0.97 correlation, they move nearly in lockstep. IIRMX charges 0.40%/yr vs 0.03%/yr for VMCPX.

Performance

IIRMX vs. VMCPX - Performance Comparison

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

Returns By Period

In the year-to-date period, IIRMX achieves a 16.20% return, which is significantly higher than VMCPX's 10.55% return. Both investments have delivered pretty close results over the past 10 years, with IIRMX having a 11.55% annualized return and VMCPX not far ahead at 11.60%.

IIRMX

• 1D: 0.23%
• 1M: 7.16%
• YTD: 16.20%
• 6M: 16.84%
• 1Y: 26.79%
• 3Y*: 18.37%
• 5Y*: 8.57%
• 10Y*: 11.55%

VMCPX

• 1D: 0.90%
• 1M: 3.68%
• YTD: 10.55%
• 6M: 10.22%
• 1Y: 18.76%
• 3Y*: 16.85%
• 5Y*: 8.12%
• 10Y*: 11.60%

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

IIRMX vs. VMCPX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
IIRMX Voya Russell Mid Cap Index Portfolio	16.20%	10.40%	14.78%	16.74%	-17.55%	21.79%	16.04%	29.16%	-9.30%	18.05%
VMCPX Vanguard Mid-Cap Index Fund Institutional Plus Shares	10.55%	11.70%	14.68%	16.55%	-18.68%	24.54%	18.20%	31.06%	-9.23%	19.28%

Correlation

The correlation between IIRMX and VMCPX is 0.84, 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	0.84
Correlation (3Y) Calculated over the trailing 3-year period	0.87
Correlation (5Y) Calculated over the trailing 5-year period	0.93
Correlation (10Y) Calculated over the trailing 10-year period	0.96
Correlation (All Time) Calculated using the full available price history since Dec 14, 2010	0.97

The correlation between IIRMX and VMCPX shifts across timeframes, from 0.84 (1 year) to 0.97 (all time), reflecting how their relationship changes across market environments.

Return for Risk

IIRMX vs. VMCPX — Risk / Return Rank

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

IIRMX

IIRMX Risk / Return Rank: 55
IIRMX Sharpe Ratio Rank: 23
IIRMX Sortino Ratio Rank: 28
IIRMX Omega Ratio Rank: 43
IIRMX Calmar Ratio Rank: 90
IIRMX Martin Ratio Rank: 93

VMCPX

VMCPX Risk / Return Rank: 36
VMCPX Sharpe Ratio Rank: 32
VMCPX Sortino Ratio Rank: 31
VMCPX Omega Ratio Rank: 29
VMCPX Calmar Ratio Rank: 41
VMCPX Martin Ratio Rank: 44

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. VMCPX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Voya Russell Mid Cap Index Portfolio (IIRMX) and Vanguard Mid-Cap Index Fund Institutional Plus Shares (VMCPX). 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.

	IIRMX	VMCPX	Difference
Sharpe ratio Return per unit of total volatility	1.37	1.62	-0.25
Sortino ratio Return per unit of downside risk	2.20	2.31	-0.11
Omega ratio Gain probability vs. loss probability	1.35	1.28	+0.07
Calmar ratio Return relative to maximum drawdown	4.57	2.45	+2.13
Martin ratio Return relative to average drawdown	20.30	9.30	+11.00
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

IIRMX vs. VMCPX - Sharpe Ratio Comparison

The current IIRMX Sharpe Ratio is 1.37, which is comparable to the VMCPX Sharpe Ratio of 1.62. The chart below compares the historical Sharpe Ratios of IIRMX and VMCPX, 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

	IIRMX	VMCPX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.37	1.62	-0.25
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.43	0.46	-0.03
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.58	0.62	-0.04
Sharpe Ratio (All Time) Calculated using the full available price history	0.47	0.63	-0.16

Drawdowns

IIRMX vs. VMCPX - Drawdown Comparison

The maximum IIRMX drawdown since its inception was -56.44%, which is greater than VMCPX's maximum drawdown of -39.30%. Use the drawdown chart below to compare losses from any high point for IIRMX and VMCPX.

Drawdown Indicators

	IIRMX	VMCPX	Difference
Max Drawdown Largest peak-to-trough decline	-56.44%	-39.30%	-17.14%
Max Drawdown (1Y) Largest decline over 1 year	-9.61%	-8.13%	-1.48%
Max Drawdown (3Y) Largest decline over 3 years	-21.18%	-18.93%	-2.25%
Max Drawdown (5Y) Largest decline over 5 years	-26.26%	-27.54%	+1.28%
Max Drawdown (10Y) Largest decline over 10 years	-40.41%	-39.30%	-1.11%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-7.88%	-5.22%	-2.66%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.17%	2.13%	+0.04%

Volatility

IIRMX vs. VMCPX - Volatility Comparison

Voya Russell Mid Cap Index Portfolio (IIRMX) has a higher volatility of 17.09% compared to Vanguard Mid-Cap Index Fund Institutional Plus Shares (VMCPX) at 2.97%. This indicates that IIRMX's price experiences larger fluctuations and is considered to be riskier than VMCPX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	IIRMX	VMCPX	Difference
Volatility (1M) Calculated over the trailing 1-month period	17.09%	2.97%	+14.12%
Volatility (6M) Calculated over the trailing 6-month period	19.25%	9.29%	+9.96%
Volatility (1Y) Calculated over the trailing 1-year period	22.37%	12.30%	+10.07%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	20.33%	17.63%	+2.70%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	20.38%	18.92%	+1.46%

IIRMX vs. VMCPX - Expense Ratio Comparison

IIRMX has a 0.40% expense ratio, which is higher than VMCPX's 0.03% expense ratio.

Dividends

IIRMX vs. VMCPX - Dividend Comparison

IIRMX's dividend yield for the trailing twelve months is around 37.97%, more than VMCPX's 1.36% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IIRMX Voya Russell Mid Cap Index Portfolio	37.97%	13.19%	10.43%	11.78%	10.34%	10.34%	14.22%	20.78%	15.64%	8.09%	14.11%	10.13%
VMCPX Vanguard Mid-Cap Index Fund Institutional Plus Shares	1.36%	1.53%	1.50%	1.52%	1.61%	1.13%	1.45%	1.49%	1.84%	1.37%	1.47%	1.50%

Frequently Asked Questions

Can I hold both IIRMX and VMCPX in my portfolio?

IIRMX and VMCPX have a correlation of 0.84, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, IIRMX or VMCPX?

IIRMX has higher volatility (17.09%) compared to VMCPX (2.97%). In terms of maximum drawdown, IIRMX dropped -56.44% vs VMCPX's -39.30%.

Which has better risk-adjusted returns?

VMCPX currently has the higher Sharpe Ratio (1.62 vs 1.37), 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.