VMCTX vs. FXAIX

Last updated Jun 4, 2026

VMCTX (Vanguard Mega Cap Index Fund Institutional Shares) and FXAIX (Fidelity 500 Index Fund) are both mutual funds - VMCTX is a Large Cap Blend Equities fund managed by Vanguard, while FXAIX is a S&P 500 fund tracking the S&P 500 Index. Over the past 10 years, VMCTX returned 16.46%/yr vs 15.66%/yr for FXAIX. With a 1.00 correlation, they move nearly in lockstep. VMCTX charges 0.06%/yr vs 0.02%/yr for FXAIX.

Performance

VMCTX vs. FXAIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Mega Cap Index Fund Institutional Shares (VMCTX) and Fidelity 500 Index Fund (FXAIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both investments are quite close, with VMCTX having a 11.68% return and FXAIX slightly higher at 11.71%. Both investments have delivered pretty close results over the past 10 years, with VMCTX having a 16.46% annualized return and FXAIX not far behind at 15.66%.

VMCTX

• 1D: 0.04%
• 1M: 6.43%
• YTD: 11.68%
• 6M: 11.63%
• 1Y: 30.69%
• 3Y*: 24.20%
• 5Y*: 15.10%
• 10Y*: 16.46%

FXAIX

• 1D: 0.13%
• 1M: 5.80%
• YTD: 11.71%
• 6M: 11.74%
• 1Y: 28.99%
• 3Y*: 22.75%
• 5Y*: 14.28%
• 10Y*: 15.66%

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

VMCTX vs. FXAIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VMCTX Vanguard Mega Cap Index Fund Institutional Shares	11.68%	19.35%	27.18%	29.67%	-19.91%	27.57%	21.47%	31.42%	-3.47%	22.57%
FXAIX Fidelity 500 Index Fund	11.71%	17.84%	25.01%	26.29%	-18.14%	28.71%	18.42%	31.48%	-4.43%	21.82%

Correlation

The correlation between VMCTX and FXAIX is 0.99 - 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	0.99
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 May 5, 2011	1.00

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

Return for Risk

VMCTX vs. FXAIX — Risk / Return Rank

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

VMCTX

VMCTX Risk / Return Rank: 72
VMCTX Sharpe Ratio Rank: 78
VMCTX Sortino Ratio Rank: 69
VMCTX Omega Ratio Rank: 68
VMCTX Calmar Ratio Rank: 68
VMCTX Martin Ratio Rank: 76

FXAIX

FXAIX Risk / Return Rank: 73
FXAIX Sharpe Ratio Rank: 76
FXAIX Sortino Ratio Rank: 67
FXAIX Omega Ratio Rank: 67
FXAIX Calmar Ratio Rank: 74
FXAIX Martin Ratio Rank: 83

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.

VMCTX vs. FXAIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Mega Cap Index Fund Institutional Shares (VMCTX) and Fidelity 500 Index Fund (FXAIX). 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.

	VMCTX	FXAIX	Difference
Sharpe ratio Return per unit of total volatility	2.56	2.52	+0.04
Sortino ratio Return per unit of downside risk	3.47	3.42	+0.04
Omega ratio Gain probability vs. loss probability	1.46	1.46	0.00
Calmar ratio Return relative to maximum drawdown	3.19	3.36	-0.16
Martin ratio Return relative to average drawdown	14.39	15.70	-1.31
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VMCTX vs. FXAIX - Sharpe Ratio Comparison

The current VMCTX Sharpe Ratio is 2.56, which is comparable to the FXAIX Sharpe Ratio of 2.52. The chart below compares the historical Sharpe Ratios of VMCTX and FXAIX, 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

	VMCTX	FXAIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.56	2.52	+0.04
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.88	0.85	+0.03
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.90	0.87	+0.03
Sharpe Ratio (All Time) Calculated using the full available price history	0.59	0.82	-0.23

Drawdowns

VMCTX vs. FXAIX - Drawdown Comparison

The maximum VMCTX drawdown since its inception was -52.00%, which is greater than FXAIX's maximum drawdown of -33.79%. Use the drawdown chart below to compare losses from any high point for VMCTX and FXAIX.

Drawdown Indicators

	VMCTX	FXAIX	Difference
Max Drawdown Largest peak-to-trough decline	-52.00%	-33.79%	-18.21%
Max Drawdown (1Y) Largest decline over 1 year	-9.87%	-8.89%	-0.98%
Max Drawdown (3Y) Largest decline over 3 years	-19.36%	-18.76%	-0.60%
Max Drawdown (5Y) Largest decline over 5 years	-25.77%	-24.50%	-1.27%
Max Drawdown (10Y) Largest decline over 10 years	-32.96%	-33.79%	+0.83%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-7.09%	-3.79%	-3.30%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.19%	1.90%	+0.29%

Volatility

VMCTX vs. FXAIX - Volatility Comparison

Vanguard Mega Cap Index Fund Institutional Shares (VMCTX) and Fidelity 500 Index Fund (FXAIX) have volatilities of 2.93% and 2.83%, 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

	VMCTX	FXAIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.93%	2.83%	+0.10%
Volatility (6M) Calculated over the trailing 6-month period	9.29%	8.97%	+0.32%
Volatility (1Y) Calculated over the trailing 1-year period	12.32%	11.86%	+0.46%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.34%	16.91%	+0.43%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.28%	18.07%	+0.21%

VMCTX vs. FXAIX - Expense Ratio Comparison

VMCTX has a 0.06% expense ratio, which is higher than FXAIX's 0.02% 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

VMCTX vs. FXAIX - Dividend Comparison

VMCTX's dividend yield for the trailing twelve months is around 0.87%, less than FXAIX's 1.03% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FXAIX Fidelity 500 Index Fund	1.03%	1.11%	1.25%	1.45%	1.69%	1.22%	1.60%	2.06%	2.72%	1.97%	2.52%	2.83%
VMCTX Vanguard Mega Cap Index Fund Institutional Shares	0.87%	0.94%	1.16%	1.36%	1.66%	1.18%	1.46%	1.82%	2.11%	1.84%	2.13%	2.13%

Frequently Asked Questions

Can I hold both VMCTX and FXAIX in my portfolio?

With a correlation of 0.99, VMCTX and FXAIX 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, VMCTX or FXAIX?

VMCTX has higher volatility (2.93%) compared to FXAIX (2.83%). In terms of maximum drawdown, VMCTX dropped -52.00% vs FXAIX's -33.79%.

Which has better risk-adjusted returns?

VMCTX currently has the higher Sharpe Ratio (2.56 vs 2.52), 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.