VINIX vs. VIIIX

Last updated Jun 13, 2026

VINIX (Vanguard Institutional Index Fund Institutional 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, VINIX returned 15.50%/yr vs 15.51%/yr for VIIIX. With a 1.00 correlation, they move nearly in lockstep. VINIX charges 0.04%/yr vs 0.02%/yr for VIIIX.

Performance

VINIX vs. VIIIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Institutional Index Fund Institutional Shares (VINIX) 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 VINIX having a 8.58% return and VIIIX slightly higher at 8.59%. Both investments have delivered pretty close results over the past 10 years, with VINIX having a 15.50% annualized return and VIIIX not far ahead at 15.51%.

VINIX

• 1D: 1.75%
• 1M: -0.55%
• YTD: 8.58%
• 6M: 8.93%
• 1Y: 23.77%
• 3Y*: 21.46%
• 5Y*: 13.46%
• 10Y*: 15.50%

VIIIX

• 1D: 1.75%
• 1M: -0.55%
• YTD: 8.59%
• 6M: 8.94%
• 1Y: 23.79%
• 3Y*: 21.47%
• 5Y*: 13.48%
• 10Y*: 15.51%

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

VINIX vs. VIIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VINIX Vanguard Institutional Index Fund Institutional Shares	8.58%	17.85%	26.28%	25.77%	-18.15%	28.67%	18.40%	31.46%	-4.42%	21.79%
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares	8.59%	17.87%	26.29%	25.79%	-18.14%	28.69%	18.41%	31.48%	-4.41%	21.82%

Correlation

The correlation between VINIX 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 Jul 7, 1997	1.00

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

VINIX vs. VIIIX - Sectors Allocation Comparison

Sectors	VINIX	VIIIX
Technology	35.7%	35.7%
Financial Services	11.6%	11.6%
Communication Services	11.3%	11.3%
Consumer Cyclical	10.2%	10.2%
Healthcare	8.5%	8.5%
Industrials	8.3%	8.3%
Consumer Defensive	4.9%	4.9%
Energy	3.5%	3.5%
Utilities	2.4%	2.4%
Real Estate	1.9%	1.9%
Basic Materials	1.8%	1.8%

Return for Risk

VINIX vs. VIIIX — Risk / Return Rank

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

VINIX

VINIX Risk / Return Rank: 73
VINIX Sharpe Ratio Rank: 72
VINIX Sortino Ratio Rank: 68
VINIX Omega Ratio Rank: 68
VINIX Calmar Ratio Rank: 73
VINIX Martin Ratio Rank: 83

VIIIX

VIIIX Risk / Return Rank: 73
VIIIX Sharpe Ratio Rank: 72
VIIIX Sortino Ratio Rank: 68
VIIIX Omega Ratio Rank: 69
VIIIX Calmar Ratio Rank: 73
VIIIX 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.

VINIX vs. VIIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Institutional Index Fund Institutional Shares (VINIX) 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.

	VINIX	VIIIX	Difference
Sharpe ratio: Return per unit of total volatility	1.97	1.97	0.00
Sortino ratio: Return per unit of downside risk	2.67	2.67	0.00
Omega ratio: Gain probability vs. loss probability	1.36	1.36	0.00
Calmar ratio: Return relative to maximum drawdown	2.74	2.74	0.00
Martin ratio: Return relative to average drawdown	12.44	12.45	-0.01

VINIX vs. VIIIX - Sharpe Ratio Comparison

The current VINIX Sharpe Ratio is 1.97, which is comparable to the VIIIX Sharpe Ratio of 1.97. The chart below compares the historical Sharpe Ratios of VINIX 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

VINIX vs. VIIIX - Drawdown Comparison

The maximum VINIX drawdown since its inception was -55.19%, roughly equal to the maximum VIIIX drawdown of -55.18%. Use the drawdown chart below to compare losses from any high point for VINIX and VIIIX.

Drawdown Indicators

	VINIX	VIIIX	Difference
Max Drawdown Largest peak-to-trough decline	-55.19%	-55.18%	-0.01%
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	-24.51%	-24.50%	-0.01%
Max Drawdown (10Y) Largest decline over 10 years	-33.79%	-33.79%	0.00%
Current Drawdown Current decline from peak	-2.79%	-2.79%	0.00%
Average Drawdown Average peak-to-trough decline	-8.52%	-10.01%	+1.49%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.95%	1.95%	0.00%

Volatility

VINIX vs. VIIIX - Volatility Comparison

Vanguard Institutional Index Fund Institutional Shares (VINIX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX) have volatilities of 4.43% and 4.44%, 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

	VINIX	VIIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.43%	4.44%	-0.01%
Volatility (6M) Calculated over the trailing 6-month period	9.70%	9.70%	0.00%
Volatility (1Y) Calculated over the trailing 1-year period	12.37%	12.37%	0.00%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.96%	16.97%	-0.01%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.09%	18.09%	0.00%

VINIX vs. VIIIX - Expense Ratio Comparison

VINIX 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

VINIX vs. VIIIX - Dividend Comparison

VINIX's dividend yield for the trailing twelve months is around 2.46%, which matches VIIIX's 2.48% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares	2.48%	2.11%	3.66%	2.66%	3.39%	4.79%	3.07%	2.86%	2.45%	1.84%	2.38%	2.47%
VINIX Vanguard Institutional Index Fund Institutional Shares	2.46%	2.10%	3.64%	2.65%	3.38%	4.77%	3.06%	2.85%	2.43%	1.82%	2.36%	2.45%

Frequently Asked Questions

Can I hold both VINIX and VIIIX in my portfolio?

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

VIIIX has higher volatility (4.44%) compared to VINIX (4.43%). In terms of maximum drawdown, VINIX dropped -55.19% vs VIIIX's -55.18%.

Which has better risk-adjusted returns?

VIIIX currently has the higher Sharpe Ratio (1.97 vs 1.97), 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.