BSPIX vs. VIIIX
BSPIX (iShares S&P 500 Index Fund Institutional Class) and VIIIX (Vanguard Institutional Index Fund Institutional Plus Shares) are both S&P 500 funds tracking the S&P 500 Index, from iShares and Vanguard respectively. Both are passively managed. Over the past 10 years, BSPIX returned 15.46%/yr vs 15.74%/yr for VIIIX. With a 1.00 correlation, they move nearly in lockstep. BSPIX charges 0.10%/yr vs 0.02%/yr for VIIIX.
Performance
BSPIX vs. VIIIX - Performance Comparison
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Returns By Period
The year-to-date returns for both investments are quite close, with BSPIX having a 11.65% return and VIIIX slightly higher at 11.70%. Both investments have delivered pretty close results over the past 10 years, with BSPIX having a 15.46% annualized return and VIIIX not far ahead at 15.74%.
BSPIX
- 1D
- 0.13%
- 1M
- 5.79%
- YTD
- 11.65%
- 6M
- 11.68%
- 1Y
- 28.84%
- 3Y*
- 22.63%
- 5Y*
- 14.17%
- 10Y*
- 15.46%
VIIIX
- 1D
- 0.13%
- 1M
- 5.80%
- YTD
- 11.70%
- 6M
- 11.74%
- 1Y
- 28.99%
- 3Y*
- 23.17%
- 5Y*
- 14.42%
- 10Y*
- 15.74%
BSPIX vs. VIIIX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
BSPIX iShares S&P 500 Index Fund Institutional Class | 11.65% | 17.75% | 24.85% | 26.17% | -18.20% | 28.55% | 18.35% | 31.35% | -4.87% | 21.20% |
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares | 11.70% | 17.87% | 26.29% | 25.79% | -18.14% | 28.69% | 18.41% | 31.48% | -4.41% | 21.82% |
Correlation
The correlation between BSPIX 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 | 0.99 |
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 Jan 3, 2014 | 1.00 |
The correlation between BSPIX and VIIIX has been stable across timeframes, ranging from 0.99 to 1.00 - a consistent structural relationship.
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Return for Risk
BSPIX vs. VIIIX — Risk / Return Rank
BSPIX
VIIIX
BSPIX vs. VIIIX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares S&P 500 Index Fund Institutional Class (BSPIX) 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.
| BSPIX | VIIIX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.01 | ||
| Sortino ratioReturn per unit of downside risk | -0.02 | ||
| Omega ratioGain probability vs. loss probability | 1.46 | 1.46 | 0.00 |
| Calmar ratioReturn relative to maximum drawdown | 3.34 | 3.36 | -0.02 |
| Martin ratioReturn relative to average drawdown | 15.58 | 15.69 | -0.12 |
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month. | |||
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Sharpe Ratios by Period
| BSPIX | VIIIX | Difference | |
|---|---|---|---|
Sharpe Ratio (1Y)Calculated over the trailing 1-year period | 2.51 | 2.52 | -0.01 |
Sharpe Ratio (5Y)Calculated over the trailing 5-year period | 0.84 | 0.86 | -0.02 |
Sharpe Ratio (10Y)Calculated over the trailing 10-year period | 0.86 | 0.87 | -0.01 |
Sharpe Ratio (All Time)Calculated using the full available price history | 0.81 | 0.50 | +0.31 |
Drawdowns
BSPIX vs. VIIIX - Drawdown Comparison
The maximum BSPIX drawdown since its inception was -33.75%, smaller than the maximum VIIIX drawdown of -55.18%. Use the drawdown chart below to compare losses from any high point for BSPIX and VIIIX.
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Drawdown Indicators
| BSPIX | VIIIX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -33.75% | -55.18% | +21.43% |
Max Drawdown (1Y)Largest decline over 1 year | -8.91% | -8.90% | -0.01% |
Max Drawdown (3Y)Largest decline over 3 years | -18.74% | -18.75% | +0.01% |
Max Drawdown (5Y)Largest decline over 5 years | -24.55% | -24.50% | -0.05% |
Max Drawdown (10Y)Largest decline over 10 years | -33.75% | -33.79% | +0.04% |
Current DrawdownCurrent decline from peak | 0.00% | 0.00% | 0.00% |
Average DrawdownAverage peak-to-trough decline | -3.93% | -10.02% | +6.09% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 1.90% | 1.90% | 0.00% |
Volatility
BSPIX vs. VIIIX - Volatility Comparison
iShares S&P 500 Index Fund Institutional Class (BSPIX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX) have volatilities of 2.83% 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.
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Volatility by Period
| BSPIX | VIIIX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 2.83% | 2.83% | 0.00% |
Volatility (6M)Calculated over the trailing 6-month period | 8.97% | 8.97% | 0.00% |
Volatility (1Y)Calculated over the trailing 1-year period | 11.85% | 11.86% | -0.01% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 16.88% | 16.89% | -0.01% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 18.03% | 18.06% | -0.03% |
BSPIX vs. VIIIX - Expense Ratio Comparison
BSPIX has a 0.10% 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
BSPIX vs. VIIIX - Dividend Comparison
BSPIX's dividend yield for the trailing twelve months is around 1.50%, less than VIIIX's 2.41% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
BSPIX iShares S&P 500 Index Fund Institutional Class | 1.50% | 1.66% | 1.35% | 1.44% | 1.94% | 1.76% | 1.60% | 1.92% | 1.94% | 1.57% | 2.30% | 2.42% |
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares | 2.41% | 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
With a correlation of 1.00, BSPIX 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.
VIIIX has higher volatility (2.83%) compared to BSPIX (2.83%). In terms of maximum drawdown, BSPIX dropped -33.75% vs VIIIX's -55.18%.
VIIIX currently has the higher Sharpe Ratio (2.52 vs 2.51), 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.
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