VFIAX vs. VIIIX

Last updated Jun 26, 2026

VFIAX (Vanguard 500 Index Fund Admiral Shares) and VIIIX (Vanguard Institutional Index Fund Institutional Plus Shares) are both S&P 500 funds from Vanguard tracking the S&P 500 Index. Both are passively managed. Over the past 10 years, VFIAX returned 15.58%/yr vs 15.69%/yr for VIIIX. With a 1.00 correlation, they move nearly in lockstep. VFIAX charges 0.04%/yr vs 0.02%/yr for VIIIX.

Performance

VFIAX vs. VIIIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard 500 Index Fund Admiral Shares (VFIAX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX). 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 VFIAX having a 8.09% return and VIIIX slightly higher at 8.10%. Both investments have delivered pretty close results over the past 10 years, with VFIAX having a 15.58% annualized return and VIIIX not far ahead at 15.69%.

VFIAX

• 1D: -0.10%
• 1M: -2.04%
• YTD: 8.09%
• 6M: 6.76%
• 1Y: 22.19%
• 3Y*: 20.73%
• 5Y*: 13.01%
• 10Y*: 15.58%

VIIIX

• 1D: -0.10%
• 1M: -2.04%
• YTD: 8.10%
• 6M: 6.77%
• 1Y: 22.22%
• 3Y*: 21.18%
• 5Y*: 13.19%
• 10Y*: 15.69%

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

VFIAX vs. VIIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VFIAX Vanguard 500 Index Fund Admiral Shares	8.09%	17.83%	24.97%	26.24%	-18.16%	28.65%	18.32%	31.46%	-4.45%	21.78%
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares	8.10%	17.87%	26.29%	25.79%	-18.14%	28.69%	18.41%	31.48%	-4.41%	21.82%

Correlation

The correlation between VFIAX and VIIIX 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 Nov 13, 2000	1.00

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

VFIAX vs. VIIIX - Sectors Allocation Comparison

Sectors	VFIAX	VIIIX
Technology	39.1%	39.1%
Financial Services	10.9%	10.9%
Communication Services	10.5%	10.7%
Consumer Cyclical	9.8%	9.9%
Healthcare	8.3%	8.3%
Industrials	7.6%	7.8%
Consumer Defensive	4.5%	4.5%
Energy	3.2%	3.1%
Utilities	2.5%	2.1%
Real Estate	1.8%	1.8%
Basic Materials	1.7%	1.7%

Return for Risk

VFIAX vs. VIIIX — Risk / Return Rank

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

VFIAX

VFIAX Risk / Return Rank: 55
VFIAX Sharpe Ratio Rank: 52
VFIAX Sortino Ratio Rank: 48
VFIAX Omega Ratio Rank: 50
VFIAX Calmar Ratio Rank: 55
VFIAX Martin Ratio Rank: 68

VIIIX

VIIIX Risk / Return Rank: 55
VIIIX Sharpe Ratio Rank: 52
VIIIX Sortino Ratio Rank: 48
VIIIX Omega Ratio Rank: 50
VIIIX Calmar Ratio Rank: 56
VIIIX Martin Ratio Rank: 68

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.

VFIAX vs. VIIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard 500 Index Fund Admiral Shares (VFIAX) 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.

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.

	VFIAX	VIIIX	Difference
Sharpe ratio: Return per unit of total volatility	1.78	1.79	0.00
Sortino ratio: Return per unit of downside risk	2.44	2.44	0.00
Omega ratio: Gain probability vs. loss probability	1.32	1.32	0.00
Calmar ratio: Return relative to maximum drawdown	2.50	2.51	-0.01
Martin ratio: Return relative to average drawdown	11.19	11.22	-0.02

VFIAX vs. VIIIX - Sharpe Ratio Comparison

The current VFIAX Sharpe Ratio is 1.78, which is comparable to the VIIIX Sharpe Ratio of 1.79. The chart below compares the historical Sharpe Ratios of VFIAX 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.

Drawdowns

VFIAX vs. VIIIX - Drawdown Comparison

The maximum VFIAX drawdown since its inception was -55.20%, roughly equal to the maximum VIIIX drawdown of -55.18%. Use the drawdown chart below to compare losses from any high point for VFIAX and VIIIX.

Drawdown Indicators

	VFIAX	VIIIX	Difference
Max Drawdown Largest peak-to-trough decline	-55.20%	-55.18%	-0.02%
Max Drawdown (1Y) Largest decline over 1 year	-8.90%	-8.90%	0.00%
Max Drawdown (3Y) Largest decline over 3 years	-18.75%	-18.75%	0.00%
Max Drawdown (5Y) Largest decline over 5 years	-24.53%	-24.50%	-0.03%
Max Drawdown (10Y) Largest decline over 10 years	-33.83%	-33.79%	-0.04%
Current Drawdown Current decline from peak	-3.22%	-3.22%	0.00%
Average Drawdown Average peak-to-trough decline	-9.38%	-10.00%	+0.62%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.99%	1.99%	0.00%

Volatility

VFIAX vs. VIIIX - Volatility Comparison

Vanguard 500 Index Fund Admiral Shares (VFIAX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX) have volatilities of 4.88% and 4.88%, 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

	VFIAX	VIIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.88%	4.88%	0.00%
Volatility (6M) Calculated over the trailing 6-month period	9.90%	9.90%	0.00%
Volatility (1Y) Calculated over the trailing 1-year period	12.54%	12.54%	0.00%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.00%	16.99%	+0.01%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.08%	18.08%	0.00%

VFIAX vs. VIIIX - Expense Ratio Comparison

VFIAX has a 0.04% expense ratio, which is higher than VIIIX'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

VFIAX vs. VIIIX - Dividend Comparison

VFIAX's dividend yield for the trailing twelve months is around 1.05%, less than VIIIX's 2.80% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
VFIAX Vanguard 500 Index Fund Admiral Shares	1.05%	1.12%	1.24%	1.45%	1.68%	1.24%	1.53%	1.87%	2.05%	1.78%	2.02%	2.10%
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares	2.80%	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 VFIAX and VIIIX in my portfolio?

With a correlation of 1.00, VFIAX 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, VFIAX or VIIIX?

VIIIX has higher volatility (4.88%) compared to VFIAX (4.88%). In terms of maximum drawdown, VFIAX dropped -55.20% vs VIIIX's -55.18%.

Which has better risk-adjusted returns?

VIIIX currently has the higher Sharpe Ratio (1.79 vs 1.78), 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.