FGRTX vs. VIIIX

Last updated Jun 5, 2026

FGRTX (Fidelity Mega Cap Stock Fund) and VIIIX (Vanguard Institutional Index Fund Institutional Plus Shares) are both mutual funds - FGRTX is a Large Cap Blend Equities fund managed by Fidelity, while VIIIX is a S&P 500 fund tracking the S&P 500 Index. Over the past 10 years, FGRTX returned 16.36%/yr vs 15.65%/yr for VIIIX. With a 0.96 correlation, they move nearly in lockstep. FGRTX charges 0.61%/yr vs 0.02%/yr for VIIIX.

Performance

FGRTX vs. VIIIX - Performance Comparison

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

Returns By Period

In the year-to-date period, FGRTX achieves a 9.38% return, which is significantly lower than VIIIX's 10.88% return. Both investments have delivered pretty close results over the past 10 years, with FGRTX having a 16.36% annualized return and VIIIX not far behind at 15.65%.

FGRTX

• 1D: -1.01%
• 1M: 1.54%
• YTD: 9.38%
• 6M: 11.06%
• 1Y: 29.86%
• 3Y*: 25.16%
• 5Y*: 15.94%
• 10Y*: 16.36%

VIIIX

• 1D: -0.74%
• 1M: 4.17%
• YTD: 10.88%
• 6M: 10.80%
• 1Y: 28.02%
• 3Y*: 22.87%
• 5Y*: 14.05%
• 10Y*: 15.65%

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

FGRTX vs. VIIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FGRTX Fidelity Mega Cap Stock Fund	9.38%	26.92%	25.98%	26.51%	-8.98%	26.29%	12.96%	31.07%	-7.44%	16.98%
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares	10.88%	17.87%	26.29%	25.79%	-18.14%	28.69%	18.41%	31.48%	-4.41%	21.82%

Correlation

The correlation between FGRTX and VIIIX is 0.94, 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	0.94
Correlation (3Y) Calculated over the trailing 3-year period	0.95
Correlation (5Y) Calculated over the trailing 5-year period	0.94
Correlation (10Y) Calculated over the trailing 10-year period	0.93
Correlation (All Time) Calculated using the full available price history since Dec 29, 1998	0.96

The correlation between FGRTX and VIIIX has been stable across timeframes, ranging from 0.93 to 0.96 - a consistent structural relationship.

Return for Risk

FGRTX vs. VIIIX — Risk / Return Rank

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

FGRTX

FGRTX Risk / Return Rank: 73
FGRTX Sharpe Ratio Rank: 74
FGRTX Sortino Ratio Rank: 68
FGRTX Omega Ratio Rank: 66
FGRTX Calmar Ratio Rank: 74
FGRTX Martin Ratio Rank: 82

VIIIX

VIIIX Risk / Return Rank: 66
VIIIX Sharpe Ratio Rank: 64
VIIIX Sortino Ratio Rank: 59
VIIIX Omega Ratio Rank: 59
VIIIX Calmar Ratio Rank: 67
VIIIX Martin Ratio Rank: 79

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.

FGRTX vs. VIIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Mega Cap Stock Fund (FGRTX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX). 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.

	FGRTX	VIIIX	Difference
Sharpe ratio: Return per unit of total volatility	2.51	2.37	+0.14
Sortino ratio: Return per unit of downside risk	3.46	3.24	+0.22
Omega ratio: Gain probability vs. loss probability	1.46	1.43	+0.03
Calmar ratio: Return relative to maximum drawdown	3.36	3.17	+0.19
Martin ratio: Return relative to average drawdown	15.23	14.79	+0.44
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FGRTX vs. VIIIX - Sharpe Ratio Comparison

The current FGRTX Sharpe Ratio is 2.51, which is comparable to the VIIIX Sharpe Ratio of 2.37. The chart below compares the historical Sharpe Ratios of FGRTX and VIIIX, 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

	FGRTX	VIIIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.51	2.37	+0.14
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.96	0.84	+0.12
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.91	0.87	+0.04
Sharpe Ratio (All Time) Calculated using the full available price history	0.47	0.49	-0.02

Drawdowns

FGRTX vs. VIIIX - Drawdown Comparison

The maximum FGRTX drawdown since its inception was -56.17%, roughly equal to the maximum VIIIX drawdown of -55.18%. Use the drawdown chart below to compare losses from any high point for FGRTX and VIIIX.

Drawdown Indicators

	FGRTX	VIIIX	Difference
Max Drawdown Largest peak-to-trough decline	-56.17%	-55.18%	-0.99%
Max Drawdown (1Y) Largest decline over 1 year	-8.99%	-8.90%	-0.09%
Max Drawdown (3Y) Largest decline over 3 years	-18.51%	-18.75%	+0.24%
Max Drawdown (5Y) Largest decline over 5 years	-23.35%	-24.50%	+1.15%
Max Drawdown (10Y) Largest decline over 10 years	-35.18%	-33.79%	-1.39%
Current Drawdown Current decline from peak	-1.33%	-0.74%	-0.59%
Average Drawdown Average peak-to-trough decline	-8.72%	-10.02%	+1.30%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.98%	1.90%	+0.08%

Volatility

FGRTX vs. VIIIX - Volatility Comparison

Fidelity Mega Cap Stock Fund (FGRTX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX) have volatilities of 2.87% and 2.93%, 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

	FGRTX	VIIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.87%	2.93%	-0.06%
Volatility (6M) Calculated over the trailing 6-month period	9.09%	8.99%	+0.10%
Volatility (1Y) Calculated over the trailing 1-year period	12.02%	11.88%	+0.14%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.71%	16.89%	-0.18%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.12%	18.06%	+0.06%

FGRTX vs. VIIIX - Expense Ratio Comparison

FGRTX has a 0.61% expense ratio, which is higher than VIIIX's 0.02% expense ratio.

Dividends

FGRTX vs. VIIIX - Dividend Comparison

FGRTX's dividend yield for the trailing twelve months is around 3.55%, more than VIIIX's 2.43% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FGRTX Fidelity Mega Cap Stock Fund	3.55%	3.89%	2.68%	2.06%	4.38%	4.79%	7.96%	12.98%	21.72%	15.57%	1.97%	4.16%
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares	2.43%	2.11%	3.66%	2.66%	3.39%	4.79%	3.07%	2.86%	2.45%	1.84%	2.38%	2.47%

Frequently Asked Questions

Can I hold both FGRTX and VIIIX in my portfolio?

With a correlation of 0.94, FGRTX and VIIIX 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, FGRTX or VIIIX?

VIIIX has higher volatility (2.93%) compared to FGRTX (2.87%). In terms of maximum drawdown, FGRTX dropped -56.17% vs VIIIX's -55.18%.

Which has better risk-adjusted returns?

FGRTX currently has the higher Sharpe Ratio (2.51 vs 2.37), 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.