IIRSX vs. WEMMX

Last updated Jun 4, 2026

IIRSX (Voya Russell Small Cap Index Portfolio) and WEMMX (TETON Westwood Mighty Mites Fund) are both Small Cap Blend Equities funds. Over the past 10 years, IIRSX returned 10.91%/yr vs 9.29%/yr for WEMMX. A 0.80 correlation means they provide meaningful diversification when combined. IIRSX charges 0.45%/yr vs 1.41%/yr for WEMMX.

Performance

IIRSX vs. WEMMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Voya Russell Small Cap Index Portfolio (IIRSX) and TETON Westwood Mighty Mites Fund (WEMMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, IIRSX achieves a 19.90% return, which is significantly lower than WEMMX's 21.19% return. Over the past 10 years, IIRSX has outperformed WEMMX with an annualized return of 10.91%, while WEMMX has yielded a comparatively lower 9.29% annualized return.

IIRSX

• 1D: 0.92%
• 1M: 6.10%
• YTD: 19.90%
• 6M: 18.62%
• 1Y: 42.59%
• 3Y*: 18.82%
• 5Y*: 6.61%
• 10Y*: 10.91%

WEMMX

• 1D: 0.87%
• 1M: 5.74%
• YTD: 21.19%
• 6M: 22.91%
• 1Y: 37.84%
• 3Y*: 15.60%
• 5Y*: 5.64%
• 10Y*: 9.29%

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

IIRSX vs. WEMMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
IIRSX Voya Russell Small Cap Index Portfolio	19.90%	12.84%	11.14%	16.61%	-20.58%	14.32%	19.15%	24.63%	-11.26%	14.32%
WEMMX TETON Westwood Mighty Mites Fund	21.19%	11.02%	3.83%	13.53%	-15.37%	21.44%	10.02%	16.94%	-13.69%	15.47%

Correlation

The correlation between IIRSX and WEMMX is 0.76, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.76
Correlation (3Y) Calculated over the trailing 3-year period	0.83
Correlation (5Y) Calculated over the trailing 5-year period	0.88
Correlation (10Y) Calculated over the trailing 10-year period	0.91
Correlation (All Time) Calculated using the full available price history since Apr 30, 2002	0.80

The correlation between IIRSX and WEMMX shifts across timeframes, from 0.76 (1 year) to 0.91 (10 years), reflecting how their relationship changes across market environments.

Return for Risk

IIRSX vs. WEMMX — Risk / Return Rank

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

IIRSX

IIRSX Risk / Return Rank: 68
IIRSX Sharpe Ratio Rank: 61
IIRSX Sortino Ratio Rank: 54
IIRSX Omega Ratio Rank: 54
IIRSX Calmar Ratio Rank: 90
IIRSX Martin Ratio Rank: 84

WEMMX

WEMMX Risk / Return Rank: 65
WEMMX Sharpe Ratio Rank: 59
WEMMX Sortino Ratio Rank: 60
WEMMX Omega Ratio Rank: 49
WEMMX Calmar Ratio Rank: 88
WEMMX Martin Ratio Rank: 69

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.

IIRSX vs. WEMMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Voya Russell Small Cap Index Portfolio (IIRSX) and TETON Westwood Mighty Mites Fund (WEMMX). 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.

	IIRSX	WEMMX	Difference
Sharpe ratio: Return per unit of total volatility	2.30	2.28	+0.03
Sortino ratio: Return per unit of downside risk	3.10	3.25	-0.14
Omega ratio: Gain probability vs. loss probability	1.41	1.38	+0.02
Calmar ratio: Return relative to maximum drawdown	4.61	4.31	+0.30
Martin ratio: Return relative to average drawdown	15.85	13.24	+2.61
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

IIRSX vs. WEMMX - Sharpe Ratio Comparison

The current IIRSX Sharpe Ratio is 2.30, which is comparable to the WEMMX Sharpe Ratio of 2.28. The chart below compares the historical Sharpe Ratios of IIRSX and WEMMX, 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

	IIRSX	WEMMX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.30	2.28	+0.03
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.29	0.30	-0.01
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.46	0.46	+0.01
Sharpe Ratio (All Time) Calculated using the full available price history	0.28	0.64	-0.36

Drawdowns

IIRSX vs. WEMMX - Drawdown Comparison

The maximum IIRSX drawdown since its inception was -63.18%, which is greater than WEMMX's maximum drawdown of -42.48%. Use the drawdown chart below to compare losses from any high point for IIRSX and WEMMX.

Drawdown Indicators

	IIRSX	WEMMX	Difference
Max Drawdown Largest peak-to-trough decline	-63.18%	-42.48%	-20.70%
Max Drawdown (1Y) Largest decline over 1 year	-11.08%	-9.31%	-1.77%
Max Drawdown (3Y) Largest decline over 3 years	-27.95%	-21.44%	-6.51%
Max Drawdown (5Y) Largest decline over 5 years	-32.01%	-27.11%	-4.90%
Max Drawdown (10Y) Largest decline over 10 years	-42.32%	-41.73%	-0.59%
Current Drawdown Current decline from peak	-0.14%	0.00%	-0.14%
Average Drawdown Average peak-to-trough decline	-11.43%	-6.62%	-4.81%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.08%	3.02%	+0.06%

Volatility

IIRSX vs. WEMMX - Volatility Comparison

Voya Russell Small Cap Index Portfolio (IIRSX) has a higher volatility of 12.22% compared to TETON Westwood Mighty Mites Fund (WEMMX) at 5.22%. This indicates that IIRSX's price experiences larger fluctuations and is considered to be riskier than WEMMX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	IIRSX	WEMMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	12.22%	5.22%	+7.00%
Volatility (6M) Calculated over the trailing 6-month period	17.34%	12.44%	+4.90%
Volatility (1Y) Calculated over the trailing 1-year period	22.20%	17.64%	+4.56%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	23.60%	18.92%	+4.68%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	23.96%	20.45%	+3.51%

IIRSX vs. WEMMX - Expense Ratio Comparison

IIRSX has a 0.45% expense ratio, which is lower than WEMMX's 1.41% expense ratio.

Dividends

IIRSX vs. WEMMX - Dividend Comparison

IIRSX's dividend yield for the trailing twelve months is around 14.17%, less than WEMMX's 18.82% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IIRSX Voya Russell Small Cap Index Portfolio	14.17%	12.31%	7.55%	5.71%	11.02%	0.61%	6.29%	12.33%	8.34%	7.95%	12.75%	11.26%
WEMMX TETON Westwood Mighty Mites Fund	18.82%	22.80%	26.79%	18.86%	13.60%	15.44%	9.23%	4.11%	4.16%	6.44%	4.61%	2.35%

Frequently Asked Questions

Can I hold both IIRSX and WEMMX in my portfolio?

IIRSX and WEMMX have a correlation of 0.76, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, IIRSX or WEMMX?

IIRSX has higher volatility (12.22%) compared to WEMMX (5.22%). In terms of maximum drawdown, IIRSX dropped -63.18% vs WEMMX's -42.48%.

Which has better risk-adjusted returns?

IIRSX currently has the higher Sharpe Ratio (2.30 vs 2.28), 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.