FSMDX vs. VIMAX

Last updated Jun 23, 2026

FSMDX (Fidelity Mid Cap Index Fund) and VIMAX (Vanguard Mid-Cap Index Fund Admiral Shares) are both Mid Cap Blend Equities funds - FSMDX tracks the Russell Midcap Index while VIMAX tracks the CRSP US Mid Cap Index. Both are passively managed. Over the past 10 years, FSMDX returned 11.79%/yr vs 11.66%/yr for VIMAX. With a 0.99 correlation, they move nearly in lockstep. FSMDX charges 0.03%/yr vs 0.05%/yr for VIMAX.

Performance

FSMDX vs. VIMAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Mid Cap Index Fund (FSMDX) and Vanguard Mid-Cap Index Fund Admiral Shares (VIMAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FSMDX achieves a 13.43% return, which is significantly higher than VIMAX's 10.87% return. Both investments have delivered pretty close results over the past 10 years, with FSMDX having a 11.79% annualized return and VIMAX not far behind at 11.66%.

FSMDX

• 1D: 0.99%
• 1M: 2.77%
• YTD: 13.43%
• 6M: 11.53%
• 1Y: 22.95%
• 3Y*: 16.47%
• 5Y*: 8.89%
• 10Y*: 11.79%

VIMAX

• 1D: 0.74%
• 1M: 2.62%
• YTD: 10.87%
• 6M: 9.30%
• 1Y: 19.27%
• 3Y*: 15.56%
• 5Y*: 8.42%
• 10Y*: 11.66%

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

FSMDX vs. VIMAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FSMDX Fidelity Mid Cap Index Fund	13.43%	10.58%	15.55%	17.20%	-17.27%	22.56%	17.13%	30.53%	-9.38%	18.04%
VIMAX Vanguard Mid-Cap Index Fund Admiral Shares	10.87%	11.67%	14.66%	16.53%	-18.70%	24.51%	18.18%	31.03%	-9.24%	19.26%

Correlation

The correlation between FSMDX and VIMAX is 0.98 - 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	0.98
Correlation (3Y) Calculated over the trailing 3-year period	0.99
Correlation (5Y) Calculated over the trailing 5-year period	0.99
Correlation (10Y) Calculated over the trailing 10-year period	0.99
Correlation (All Time) Calculated using the full available price history since Sep 9, 2011	0.99

The correlation between FSMDX and VIMAX has been stable across timeframes, ranging from 0.98 to 0.99 - a consistent structural relationship.

Return for Risk

FSMDX vs. VIMAX — Risk / Return Rank

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

FSMDX

FSMDX Risk / Return Rank: 46
FSMDX Sharpe Ratio Rank: 38
FSMDX Sortino Ratio Rank: 39
FSMDX Omega Ratio Rank: 35
FSMDX Calmar Ratio Rank: 60
FSMDX Martin Ratio Rank: 57

VIMAX

VIMAX Risk / Return Rank: 37
VIMAX Sharpe Ratio Rank: 33
VIMAX Sortino Ratio Rank: 32
VIMAX Omega Ratio Rank: 30
VIMAX Calmar Ratio Rank: 44
VIMAX Martin Ratio Rank: 46

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.

FSMDX vs. VIMAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Mid Cap Index Fund (FSMDX) and Vanguard Mid-Cap Index Fund Admiral Shares (VIMAX). 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.

	FSMDX	VIMAX	Difference
Sharpe ratio: Return per unit of total volatility	1.68	1.54	+0.14
Sortino ratio: Return per unit of downside risk	2.40	2.18	+0.22
Omega ratio: Gain probability vs. loss probability	1.29	1.27	+0.02
Calmar ratio: Return relative to maximum drawdown	2.84	2.41	+0.42
Martin ratio: Return relative to average drawdown	10.86	9.08	+1.78

FSMDX vs. VIMAX - Sharpe Ratio Comparison

The current FSMDX Sharpe Ratio is 1.68, which is comparable to the VIMAX Sharpe Ratio of 1.54. The chart below compares the historical Sharpe Ratios of FSMDX and VIMAX, 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

FSMDX vs. VIMAX - Drawdown Comparison

The maximum FSMDX drawdown since its inception was -40.35%, smaller than the maximum VIMAX drawdown of -58.88%. Use the drawdown chart below to compare losses from any high point for FSMDX and VIMAX.

Drawdown Indicators

	FSMDX	VIMAX	Difference
Max Drawdown Largest peak-to-trough decline	-40.35%	-58.88%	+18.53%
Max Drawdown (1Y) Largest decline over 1 year	-8.16%	-8.13%	-0.03%
Max Drawdown (3Y) Largest decline over 3 years	-20.92%	-18.93%	-1.99%
Max Drawdown (5Y) Largest decline over 5 years	-26.07%	-27.55%	+1.48%
Max Drawdown (10Y) Largest decline over 10 years	-40.35%	-39.30%	-1.05%
Current Drawdown Current decline from peak	-0.78%	-0.84%	+0.06%
Average Drawdown Average peak-to-trough decline	-4.94%	-8.10%	+3.16%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.13%	2.16%	-0.03%

Volatility

FSMDX vs. VIMAX - Volatility Comparison

Fidelity Mid Cap Index Fund (FSMDX) and Vanguard Mid-Cap Index Fund Admiral Shares (VIMAX) have volatilities of 4.57% and 4.45%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FSMDX	VIMAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.57%	4.45%	+0.12%
Volatility (6M) Calculated over the trailing 6-month period	10.47%	9.87%	+0.60%
Volatility (1Y) Calculated over the trailing 1-year period	13.82%	12.77%	+1.05%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	18.33%	17.70%	+0.63%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.35%	18.95%	+0.40%

FSMDX vs. VIMAX - Expense Ratio Comparison

FSMDX has a 0.03% expense ratio, which is lower than VIMAX's 0.05% 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

FSMDX vs. VIMAX - Dividend Comparison

FSMDX's dividend yield for the trailing twelve months is around 0.97%, less than VIMAX's 1.34% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FSMDX Fidelity Mid Cap Index Fund	0.97%	1.10%	2.46%	1.39%	2.07%	3.35%	2.34%	2.86%	2.21%	2.17%	2.23%	2.84%
VIMAX Vanguard Mid-Cap Index Fund Admiral Shares	1.34%	1.51%	1.48%	1.50%	1.59%	1.11%	1.44%	1.47%	1.82%	1.35%	1.45%	1.47%

Frequently Asked Questions

Can I hold both FSMDX and VIMAX in my portfolio?

With a correlation of 0.98, FSMDX and VIMAX 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, FSMDX or VIMAX?

FSMDX has higher volatility (4.57%) compared to VIMAX (4.45%). In terms of maximum drawdown, FSMDX dropped -40.35% vs VIMAX's -58.88%.

Which has better risk-adjusted returns?

FSMDX currently has the higher Sharpe Ratio (1.68 vs 1.54), 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.