WFSPX vs. VINIX

Last updated Jun 24, 2026

WFSPX (iShares S&P 500 Index Fund Class K) and VINIX (Vanguard Institutional Index Fund Institutional Shares) are both S&P 500 funds tracking the S&P 500 Index, from BlackRock and Vanguard respectively. Both are passively managed. Over the past 10 years, WFSPX returned 15.68%/yr vs 15.85%/yr for VINIX. With a 0.99 correlation, they move nearly in lockstep. WFSPX charges 0.03%/yr vs 0.04%/yr for VINIX.

Performance

WFSPX vs. VINIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares S&P 500 Index Fund Class K (WFSPX) and Vanguard Institutional Index Fund Institutional Shares (VINIX). 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 WFSPX having a 9.77% return and VINIX slightly higher at 9.78%. Both investments have delivered pretty close results over the past 10 years, with WFSPX having a 15.68% annualized return and VINIX not far ahead at 15.85%.

WFSPX

• 1D: -0.36%
• 1M: 0.10%
• YTD: 9.77%
• 6M: 8.77%
• 1Y: 25.45%
• 3Y*: 21.35%
• 5Y*: 13.57%
• 10Y*: 15.68%

VINIX

• 1D: -0.37%
• 1M: 0.10%
• YTD: 9.78%
• 6M: 8.78%
• 1Y: 25.49%
• 3Y*: 21.79%
• 5Y*: 13.73%
• 10Y*: 15.85%

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

WFSPX vs. VINIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
WFSPX iShares S&P 500 Index Fund Class K	9.77%	17.83%	24.94%	26.25%	-18.14%	28.63%	18.43%	31.45%	-4.83%	21.27%
VINIX Vanguard Institutional Index Fund Institutional Shares	9.78%	17.85%	26.28%	25.77%	-18.15%	28.67%	18.40%	31.46%	-4.42%	21.79%

Correlation

The correlation between WFSPX and VINIX 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 2, 1993	0.99

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

Return for Risk

WFSPX vs. VINIX — Risk / Return Rank

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

WFSPX

WFSPX Risk / Return Rank: 65
WFSPX Sharpe Ratio Rank: 63
WFSPX Sortino Ratio Rank: 57
WFSPX Omega Ratio Rank: 59
WFSPX Calmar Ratio Rank: 67
WFSPX Martin Ratio Rank: 78

VINIX

VINIX Risk / Return Rank: 65
VINIX Sharpe Ratio Rank: 64
VINIX Sortino Ratio Rank: 57
VINIX Omega Ratio Rank: 59
VINIX Calmar Ratio Rank: 68
VINIX Martin Ratio Rank: 78

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.

WFSPX vs. VINIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares S&P 500 Index Fund Class K (WFSPX) and Vanguard Institutional Index Fund Institutional Shares (VINIX). 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.

	WFSPX	VINIX	Difference
Sharpe ratio: Return per unit of total volatility	2.15	2.15	0.00
Sortino ratio: Return per unit of downside risk	2.90	2.91	0.00
Omega ratio: Gain probability vs. loss probability	1.39	1.39	0.00
Calmar ratio: Return relative to maximum drawdown	3.01	3.01	0.00
Martin ratio: Return relative to average drawdown	13.58	13.61	-0.03

WFSPX vs. VINIX - Sharpe Ratio Comparison

The current WFSPX Sharpe Ratio is 2.15, which is comparable to the VINIX Sharpe Ratio of 2.15. The chart below compares the historical Sharpe Ratios of WFSPX and VINIX, 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

WFSPX vs. VINIX - Drawdown Comparison

The maximum WFSPX drawdown since its inception was -58.21%, which is greater than VINIX's maximum drawdown of -55.19%. Use the drawdown chart below to compare losses from any high point for WFSPX and VINIX.

Drawdown Indicators

	WFSPX	VINIX	Difference
Max Drawdown Largest peak-to-trough decline	-58.21%	-55.19%	-3.02%
Max Drawdown (1Y) Largest decline over 1 year	-8.90%	-8.90%	0.00%
Max Drawdown (3Y) Largest decline over 3 years	-18.74%	-18.75%	+0.01%
Max Drawdown (5Y) Largest decline over 5 years	-24.51%	-24.51%	0.00%
Max Drawdown (10Y) Largest decline over 10 years	-33.74%	-33.79%	+0.05%
Current Drawdown Current decline from peak	-1.72%	-1.72%	0.00%
Average Drawdown Average peak-to-trough decline	-12.76%	-8.52%	-4.24%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.97%	1.97%	0.00%

Volatility

WFSPX vs. VINIX - Volatility Comparison

iShares S&P 500 Index Fund Class K (WFSPX) and Vanguard Institutional Index Fund Institutional Shares (VINIX) have volatilities of 4.67% and 4.67%, 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

	WFSPX	VINIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.67%	4.67%	0.00%
Volatility (6M) Calculated over the trailing 6-month period	9.83%	9.84%	-0.01%
Volatility (1Y) Calculated over the trailing 1-year period	12.49%	12.50%	-0.01%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.97%	16.98%	-0.01%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.07%	18.11%	-0.04%

WFSPX vs. VINIX - Expense Ratio Comparison

WFSPX has a 0.03% expense ratio, which is lower than VINIX's 0.04% 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

WFSPX vs. VINIX - Dividend Comparison

WFSPX's dividend yield for the trailing twelve months is around 1.59%, less than VINIX's 2.44% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
VINIX Vanguard Institutional Index Fund Institutional Shares	2.44%	2.10%	3.64%	2.65%	3.38%	4.77%	3.06%	2.85%	2.43%	1.82%	2.36%	2.45%
WFSPX iShares S&P 500 Index Fund Class K	1.59%	1.72%	1.41%	1.50%	2.02%	1.82%	1.66%	1.99%	2.00%	1.62%	2.37%	2.49%

Frequently Asked Questions

Can I hold both WFSPX and VINIX in my portfolio?

With a correlation of 1.00, WFSPX and VINIX 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, WFSPX or VINIX?

VINIX has higher volatility (4.67%) compared to WFSPX (4.67%). In terms of maximum drawdown, WFSPX dropped -58.21% vs VINIX's -55.19%.

Which has better risk-adjusted returns?

VINIX currently has the higher Sharpe Ratio (2.15 vs 2.15), 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.