VBMPX vs. VIIIX
VBMPX (Vanguard Total Bond Market Index Fund Institutional Plus Shares) and VIIIX (Vanguard Institutional Index Fund Institutional Plus Shares) are both mutual funds - VBMPX is a Total Bond Market fund managed by Vanguard, while VIIIX is a S&P 500 fund tracking the S&P 500 Index. Over the past 10 years, VBMPX returned 1.57%/yr vs 15.65%/yr for VIIIX. At a correlation of -0.16, they often move in opposite directions. VBMPX charges 0.03%/yr vs 0.02%/yr for VIIIX.
Performance
VBMPX vs. VIIIX - Performance Comparison
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Returns By Period
In the year-to-date period, VBMPX achieves a 0.43% return, which is significantly lower than VIIIX's 10.19% return. Over the past 10 years, VBMPX has underperformed VIIIX with an annualized return of 1.57%, while VIIIX has yielded a comparatively higher 15.65% annualized return.
VBMPX
- 1D
- 0.31%
- 1M
- 0.97%
- YTD
- 0.43%
- 6M
- 0.77%
- 1Y
- 4.70%
- 3Y*
- 4.10%
- 5Y*
- 0.03%
- 10Y*
- 1.57%
VIIIX
- 1D
- 1.09%
- 1M
- 0.47%
- YTD
- 10.19%
- 6M
- 9.68%
- 1Y
- 27.18%
- 3Y*
- 21.39%
- 5Y*
- 14.24%
- 10Y*
- 15.65%
VBMPX vs. VIIIX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
VBMPX Vanguard Total Bond Market Index Fund Institutional Plus Shares | 0.43% | 7.18% | 1.27% | 5.75% | -13.14% | -1.95% | 7.75% | 8.74% | -0.24% | 3.58% |
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares | 10.19% | 17.87% | 26.29% | 25.79% | -18.14% | 28.69% | 18.41% | 31.48% | -4.41% | 21.82% |
Correlation
The correlation between VBMPX and VIIIX is 0.29, which is low. Their price movements are largely independent, making them effective diversification partners.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.29 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.20 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.14 |
Correlation (10Y) Calculated over the trailing 10-year period | -0.01 |
Correlation (All Time) Calculated using the full available price history since Feb 5, 2010 | -0.16 |
The correlation between VBMPX and VIIIX shifts across timeframes, from -0.16 (all time) to 0.29 (1 year), reflecting how their relationship changes across market environments.
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Return for Risk
VBMPX vs. VIIIX — Risk / Return Rank
VBMPX
VIIIX
VBMPX vs. VIIIX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for Vanguard Total Bond Market Index Fund Institutional Plus Shares (VBMPX) 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.
| VBMPX | VIIIX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.96 | ||
| Sortino ratioReturn per unit of downside risk | -1.11 | ||
| Omega ratioGain probability vs. loss probability | 1.21 | 1.39 | -0.18 |
| Calmar ratioReturn relative to maximum drawdown | 1.64 | 3.04 | -1.40 |
| Martin ratioReturn relative to average drawdown | 4.65 | 13.74 | -9.09 |
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Drawdowns
VBMPX vs. VIIIX - Drawdown Comparison
The maximum VBMPX drawdown since its inception was -18.90%, smaller than the maximum VIIIX drawdown of -55.18%. Use the drawdown chart below to compare losses from any high point for VBMPX and VIIIX.
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Drawdown Indicators
| VBMPX | VIIIX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -18.90% | -55.18% | +36.28% |
Max Drawdown (1Y)Largest decline over 1 year | -2.89% | -8.90% | +6.01% |
Max Drawdown (3Y)Largest decline over 3 years | -5.99% | -18.75% | +12.76% |
Max Drawdown (5Y)Largest decline over 5 years | -18.12% | -24.50% | +6.38% |
Max Drawdown (10Y)Largest decline over 10 years | -18.90% | -33.79% | +14.89% |
Current DrawdownCurrent decline from peak | -2.23% | -1.36% | -0.87% |
Average DrawdownAverage peak-to-trough decline | -3.53% | -10.00% | +6.47% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 1.01% | 1.96% | -0.95% |
Volatility
VBMPX vs. VIIIX - Volatility Comparison
The current volatility for Vanguard Total Bond Market Index Fund Institutional Plus Shares (VBMPX) is 1.21%, while Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX) has a volatility of 4.77%. This indicates that VBMPX experiences smaller price fluctuations and is considered to be less risky than VIIIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| VBMPX | VIIIX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.21% | 4.77% | -3.56% |
Volatility (6M)Calculated over the trailing 6-month period | 2.86% | 9.91% | -7.05% |
Volatility (1Y)Calculated over the trailing 1-year period | 3.90% | 12.47% | -8.57% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.02% | 16.99% | -10.97% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 4.99% | 18.10% | -13.11% |
VBMPX vs. VIIIX - Expense Ratio Comparison
VBMPX has a 0.03% 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
VBMPX vs. VIIIX - Dividend Comparison
VBMPX's dividend yield for the trailing twelve months is around 4.00%, more than VIIIX's 2.44% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
VBMPX Vanguard Total Bond Market Index Fund Institutional Plus Shares | 4.00% | 3.88% | 3.69% | 3.11% | 2.61% | 1.81% | 2.41% | 2.75% | 2.58% | 2.58% | 2.55% | 2.85% |
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares | 2.44% | 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
VBMPX and VIIIX have a correlation of 0.29, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
VIIIX has higher volatility (4.77%) compared to VBMPX (1.21%). In terms of maximum drawdown, VBMPX dropped -18.90% vs VIIIX's -55.18%.
VIIIX currently has the higher Sharpe Ratio (2.17 vs 1.21), 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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