VO vs. IWM

Last updated Jun 12, 2026

VO (Vanguard Mid-Cap ETF) and IWM (iShares Russell 2000 ETF) are both exchange-traded funds - VO is a Mid Cap Blend Equities fund tracking the CRSP US Mid Cap Index, while IWM is a Small Cap Blend Equities fund tracking the Russell 2000 Index. Both are passively managed. Over the past 10 years, VO returned 11.63%/yr vs 11.14%/yr for IWM. Their correlation of 0.91 suggests significant overlap in exposure. VO charges 0.03%/yr vs 0.19%/yr for IWM.

Performance

VO vs. IWM - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Mid-Cap ETF (VO) and iShares Russell 2000 ETF (IWM). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VO achieves a 9.36% return, which is significantly lower than IWM's 18.19% return. Both investments have delivered pretty close results over the past 10 years, with VO having a 11.63% annualized return and IWM not far behind at 11.14%.

VO

• 1D: 1.86%
• 1M: 2.37%
• YTD: 9.36%
• 6M: 7.17%
• 1Y: 17.42%
• 3Y*: 15.76%
• 5Y*: 7.58%
• 10Y*: 11.63%

IWM

• 1D: 2.96%
• 1M: 2.77%
• YTD: 18.19%
• 6M: 13.23%
• 1Y: 37.41%
• 3Y*: 17.34%
• 5Y*: 5.88%
• 10Y*: 11.14%

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

VO vs. IWM - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VO Vanguard Mid-Cap ETF	9.36%	11.62%	15.31%	16.03%	-18.73%	24.70%	18.10%	30.98%	-9.24%	19.28%
IWM iShares Russell 2000 ETF	18.19%	12.66%	11.38%	16.83%	-20.48%	14.54%	20.03%	25.39%	-11.12%	14.58%

Correlation

The correlation between VO and IWM is 0.87, 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	0.87
Correlation (3Y) Calculated over the trailing 3-year period	0.90
Correlation (5Y) Calculated over the trailing 5-year period	0.92
Correlation (10Y) Calculated over the trailing 10-year period	0.91
Correlation (All Time) Calculated using the full available price history since Jan 30, 2004	0.91

The correlation between VO and IWM has been stable across timeframes, ranging from 0.87 to 0.92 - a consistent structural relationship.

VO vs. IWM - Sectors Allocation Comparison

Sectors	VO	IWM
Technology	18.6%	19.5%
Industrials	17.9%	17.2%
Financial Services	12.8%	15.6%
Consumer Cyclical	8.6%	7.9%
Energy	8.5%	5.8%
Utilities	8.3%	3.0%
Healthcare	7.6%	16.1%
Real Estate	5.4%	5.6%
Consumer Defensive	4.8%	2.1%
Basic Materials	4.2%	4.5%
Communication Services	3.1%	2.1%

Return for Risk

VO vs. IWM — Risk / Return Rank

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

VO

VO Risk / Return Rank: 50
VO Sharpe Ratio Rank: 48
VO Sortino Ratio Rank: 48
VO Omega Ratio Rank: 45
VO Calmar Ratio Rank: 52
VO Martin Ratio Rank: 56

IWM

IWM Risk / Return Rank: 72
IWM Sharpe Ratio Rank: 72
IWM Sortino Ratio Rank: 71
IWM Omega Ratio Rank: 63
IWM Calmar Ratio Rank: 79
IWM Martin Ratio Rank: 77

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.

VO vs. IWM - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Mid-Cap ETF (VO) and iShares Russell 2000 ETF (IWM). 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.

	VO	IWM	Difference
Sharpe ratio: Return per unit of total volatility	1.38	1.91	-0.53
Sortino ratio: Return per unit of downside risk	1.98	2.65	-0.67
Omega ratio: Gain probability vs. loss probability	1.24	1.31	-0.07
Calmar ratio: Return relative to maximum drawdown	2.14	3.41	-1.27
Martin ratio: Return relative to average drawdown	8.08	12.04	-3.96

VO vs. IWM - Sharpe Ratio Comparison

The current VO Sharpe Ratio is 1.38, which is comparable to the IWM Sharpe Ratio of 1.91. The chart below compares the historical Sharpe Ratios of VO and IWM, 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

VO vs. IWM - Drawdown Comparison

The maximum VO drawdown since its inception was -58.87%, roughly equal to the maximum IWM drawdown of -59.05%. Use the drawdown chart below to compare losses from any high point for VO and IWM.

Drawdown Indicators

	VO	IWM	Difference
Max Drawdown Largest peak-to-trough decline	-58.87%	-59.05%	+0.18%
Max Drawdown (1Y) Largest decline over 1 year	-8.17%	-11.03%	+2.86%
Max Drawdown (3Y) Largest decline over 3 years	-19.02%	-27.50%	+8.48%
Max Drawdown (5Y) Largest decline over 5 years	-27.57%	-31.91%	+4.34%
Max Drawdown (10Y) Largest decline over 10 years	-39.37%	-41.13%	+1.76%
Current Drawdown Current decline from peak	-1.41%	-0.55%	-0.86%
Average Drawdown Average peak-to-trough decline	-7.86%	-10.76%	+2.90%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.16%	3.12%	-0.96%

Volatility

VO vs. IWM - Volatility Comparison

The current volatility for Vanguard Mid-Cap ETF (VO) is 4.25%, while iShares Russell 2000 ETF (IWM) has a volatility of 7.12%. This indicates that VO experiences smaller price fluctuations and is considered to be less risky than IWM based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VO	IWM	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.25%	7.12%	-2.87%
Volatility (6M) Calculated over the trailing 6-month period	9.76%	14.32%	-4.56%
Volatility (1Y) Calculated over the trailing 1-year period	12.72%	19.72%	-7.00%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.65%	22.61%	-4.96%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.96%	23.08%	-4.12%

VO vs. IWM - Expense Ratio Comparison

VO has a 0.03% expense ratio, which is lower than IWM's 0.19% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

VO vs. IWM - Dividend Comparison

VO's dividend yield for the trailing twelve months is around 1.37%, more than IWM's 0.87% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IWM iShares Russell 2000 ETF	0.87%	1.04%	1.15%	1.35%	1.48%	0.94%	1.04%	1.26%	1.40%	1.26%	1.38%	1.54%
VO Vanguard Mid-Cap ETF	1.37%	1.52%	1.49%	1.52%	1.60%	1.12%	1.45%	1.48%	1.82%	1.35%	1.45%	1.47%

Frequently Asked Questions

Can I hold both VO and IWM in my portfolio?

VO and IWM have a correlation of 0.87, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VO or IWM?

IWM has higher volatility (7.12%) compared to VO (4.25%). In terms of maximum drawdown, VO dropped -58.87% vs IWM's -59.05%.

Which ETF is better, VO or IWM?

On 10-year performance, VO leads with 11.63% vs 11.14% for IWM. On fees, VO is cheaper at 0.03% per year. On volatility, VO has been the lower-risk option at 4.25%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, VO or IWM?

Over the 10-year period, VO has performed better with a 11.63% return vs 11.14%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, VO or IWM?

VO is cheaper with a 0.03% expense ratio, compared with 0.19% for IWM.

Which ETF pays a higher dividend yield, VO or IWM?

VO has the higher dividend yield at 1.37%, compared with 0.87% for IWM.

What is the main difference between VO and IWM?

VO is categorized as Mid Cap Blend Equities, while IWM is Small Cap Blend Equities. VO tracks CRSP US Mid Cap Index, while IWM tracks Russell 2000 Index. They also come from different issuers: Vanguard and iShares. Their fees differ too: 0.03% for VO and 0.19% for IWM.

Which has better risk-adjusted returns?

IWM currently has the higher Sharpe Ratio (1.91 vs 1.38), 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.