VIMSX vs. VO

Last updated Jul 14, 2026

VIMSX (Vanguard Mid Cap Index Fund) and VO (Vanguard Mid-Cap ETF) are both Mid Cap Blend Equities funds from Vanguard. Over the past 10 years, VIMSX returned 11.28%/yr vs 11.46%/yr for VO. With a 0.99 correlation, they move nearly in lockstep. VIMSX charges 0.17%/yr vs 0.03%/yr for VO.

Performance

VIMSX vs. VO - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Mid Cap Index Fund (VIMSX) and Vanguard Mid-Cap ETF (VO). 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 VIMSX having a 12.27% return and VO slightly lower at 12.19%. Both investments have delivered pretty close results over the past 10 years, with VIMSX having a 11.28% annualized return and VO not far ahead at 11.46%.

VIMSX

• 1D: 0.16%
• 1M: 1.71%
• 6M: 8.89%
• YTD: 12.27%
• 1Y: 16.19%
• 3Y*: 14.54%
• 5Y*: 7.63%
• 10Y*: 11.28%

VO

• 1D: -0.12%
• 1M: 1.60%
• 6M: 8.84%
• YTD: 12.19%
• 1Y: 16.23%
• 3Y*: 14.65%
• 5Y*: 8.18%
• 10Y*: 11.46%

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

VIMSX vs. VO - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VIMSX Vanguard Mid Cap Index Fund	12.27%	11.08%	14.52%	16.40%	-18.80%	24.36%	18.04%	30.85%	-9.35%	19.12%
VO Vanguard Mid-Cap ETF	12.19%	11.62%	15.31%	16.03%	-18.73%	24.70%	18.10%	30.98%	-9.24%	19.28%

Correlation

The correlation between VIMSX and VO is 1.00 - 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	1.00
Correlation (3Y) Calculated over the trailing 3-year period	1.00
Correlation (5Y) Calculated over the trailing 5-year period	1.00
Correlation (10Y) Calculated over the trailing 10-year period	1.00
Correlation (All Time) Calculated using the full available price history since Jan 30, 2004	0.99

The correlation between VIMSX and VO has been stable across timeframes, ranging from 0.99 to 1.00 - a consistent structural relationship.

Return for Risk

VIMSX vs. VO — Risk / Return Rank

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

VIMSX

VIMSX Risk / Return Rank: 35
VIMSX Sharpe Ratio Rank: 32
VIMSX Sortino Ratio Rank: 31
VIMSX Omega Ratio Rank: 29
VIMSX Calmar Ratio Rank: 39
VIMSX Martin Ratio Rank: 42

VO

VO Risk / Return Rank: 48
VO Sharpe Ratio Rank: 45
VO Sortino Ratio Rank: 46
VO Omega Ratio Rank: 43
VO Calmar Ratio Rank: 50
VO Martin Ratio Rank: 55

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.

VIMSX vs. VO - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Mid Cap Index Fund (VIMSX) and Vanguard Mid-Cap ETF (VO). 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.

	VIMSX	VO	Difference
Sharpe ratio: Return per unit of total volatility	1.22	1.28	-0.06
Sortino ratio: Return per unit of downside risk	1.77	1.86	-0.09
Omega ratio: Gain probability vs. loss probability	1.21	1.23	-0.01
Calmar ratio: Return relative to maximum drawdown	1.91	2.00	-0.09
Martin ratio: Return relative to average drawdown	7.16	7.53	-0.36

VIMSX vs. VO - Sharpe Ratio Comparison

The current VIMSX Sharpe Ratio is 1.22, which is comparable to the VO Sharpe Ratio of 1.28. The chart below compares the historical Sharpe Ratios of VIMSX and VO, 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

VIMSX vs. VO - Drawdown Comparison

The maximum VIMSX drawdown since its inception was -58.96%, roughly equal to the maximum VO drawdown of -58.87%. Use the drawdown chart below to compare losses from any high point for VIMSX and VO.

Drawdown Indicators

	VIMSX	VO	Difference
Max Drawdown Largest peak-to-trough decline	-58.96%	-58.87%	-0.09%
Max Drawdown (1Y) Largest decline over 1 year	-8.14%	-8.17%	+0.03%
Max Drawdown (3Y) Largest decline over 3 years	-19.31%	-19.02%	-0.29%
Max Drawdown (5Y) Largest decline over 5 years	-27.63%	-27.57%	-0.06%
Max Drawdown (10Y) Largest decline over 10 years	-39.29%	-39.37%	+0.08%
Current Drawdown Current decline from peak	0.00%	-0.12%	+0.12%
Average Drawdown Average peak-to-trough decline	-8.05%	-7.83%	-0.22%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.16%	2.16%	0.00%

Volatility

VIMSX vs. VO - Volatility Comparison

Vanguard Mid Cap Index Fund (VIMSX) has a higher volatility of 3.80% compared to Vanguard Mid-Cap ETF (VO) at 3.38%. This indicates that VIMSX's price experiences larger fluctuations and is considered to be riskier than VO based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VIMSX	VO	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.80%	3.38%	+0.42%
Volatility (6M) Calculated over the trailing 6-month period	9.66%	9.62%	+0.04%
Volatility (1Y) Calculated over the trailing 1-year period	12.72%	12.74%	-0.02%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.69%	17.64%	+0.05%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.85%	18.87%	-0.02%

VIMSX vs. VO - Expense Ratio Comparison

VIMSX has a 0.17% expense ratio, which is higher than VO's 0.03% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

VIMSX vs. VO - Dividend Comparison

VIMSX's dividend yield for the trailing twelve months is around 1.20%, less than VO's 1.32% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
VIMSX Vanguard Mid Cap Index Fund	1.20%	1.03%	1.37%	1.39%	1.46%	1.00%	1.34%	1.37%	1.68%	1.24%	1.34%	1.33%
VO Vanguard Mid-Cap ETF	1.32%	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 VIMSX and VO in my portfolio?

With a correlation of 1.00, VIMSX and VO 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, VIMSX or VO?

VIMSX has higher volatility (3.80%) compared to VO (3.38%). In terms of maximum drawdown, VIMSX dropped -58.96% vs VO's -58.87%.

Which has better risk-adjusted returns?

VO currently has the higher Sharpe Ratio (1.28 vs 1.22), 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.