WFBIX vs. VCPIX
WFBIX (iShares U.S. Aggregate Bond Index Fund) and VCPIX (Vanguard Core-Plus Bond Fund Investor Shares) are both mutual funds - WFBIX is a Intermediate Core Bond fund managed by BlackRock, while VCPIX is a Total Bond Market fund managed by Vanguard. Over the past 3 years, WFBIX returned 5.33%/yr vs 5.30%/yr for VCPIX. With a 0.95 correlation, they move nearly in lockstep. WFBIX charges 0.05%/yr vs 0.30%/yr for VCPIX.
Performance
WFBIX vs. VCPIX - Performance Comparison
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Returns By Period
In the year-to-date period, WFBIX achieves a 0.43% return, which is significantly lower than VCPIX's 0.73% return.
WFBIX
- 1D
- 0.55%
- 1M
- 0.56%
- YTD
- 0.43%
- 6M
- 0.98%
- 1Y
- 4.88%
- 3Y*
- 5.33%
- 5Y*
- 0.82%
- 10Y*
- 1.91%
VCPIX
- 1D
- 0.47%
- 1M
- 0.51%
- YTD
- 0.73%
- 6M
- 1.25%
- 1Y
- 5.54%
- 3Y*
- 5.30%
- 5Y*
- —
- 10Y*
- —
WFBIX vs. VCPIX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | |
|---|---|---|---|---|---|---|
WFBIX iShares U.S. Aggregate Bond Index Fund | 0.43% | 7.16% | 1.43% | 9.65% | -13.03% | -0.04% |
VCPIX Vanguard Core-Plus Bond Fund Investor Shares | 0.73% | 8.01% | 2.83% | 6.64% | -12.68% | 0.35% |
Correlation
The correlation between WFBIX and VCPIX is 0.93, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.93 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.94 |
Correlation (All Time) Calculated using the full available price history since Oct 14, 2021 | 0.95 |
The correlation between WFBIX and VCPIX has been stable across timeframes, ranging from 0.93 to 0.95 - a consistent structural relationship.
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Return for Risk
WFBIX vs. VCPIX — Risk / Return Rank
WFBIX
VCPIX
WFBIX vs. VCPIX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares U.S. Aggregate Bond Index Fund (WFBIX) and Vanguard Core-Plus Bond Fund Investor Shares (VCPIX). 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.
| WFBIX | VCPIX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.34 | ||
| Sortino ratioReturn per unit of downside risk | -0.48 | ||
| Omega ratioGain probability vs. loss probability | 1.22 | 1.29 | -0.06 |
| Calmar ratioReturn relative to maximum drawdown | 1.62 | 2.05 | -0.42 |
| Martin ratioReturn relative to average drawdown | 4.66 | 6.44 | -1.78 |
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Drawdowns
WFBIX vs. VCPIX - Drawdown Comparison
The maximum WFBIX drawdown since its inception was -18.68%, which is greater than VCPIX's maximum drawdown of -17.33%. Use the drawdown chart below to compare losses from any high point for WFBIX and VCPIX.
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Drawdown Indicators
| WFBIX | VCPIX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -18.68% | -17.33% | -1.35% |
Max Drawdown (1Y)Largest decline over 1 year | -3.02% | -2.72% | -0.30% |
Max Drawdown (3Y)Largest decline over 3 years | -6.09% | -5.68% | -0.41% |
Max Drawdown (5Y)Largest decline over 5 years | -17.84% | — | — |
Max Drawdown (10Y)Largest decline over 10 years | -18.68% | — | — |
Current DrawdownCurrent decline from peak | -1.50% | -1.01% | -0.49% |
Average DrawdownAverage peak-to-trough decline | -2.26% | -6.56% | +4.30% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 1.05% | 0.86% | +0.19% |
Volatility
WFBIX vs. VCPIX - Volatility Comparison
iShares U.S. Aggregate Bond Index Fund (WFBIX) has a higher volatility of 1.36% compared to Vanguard Core-Plus Bond Fund Investor Shares (VCPIX) at 1.22%. This indicates that WFBIX's price experiences larger fluctuations and is considered to be riskier than VCPIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| WFBIX | VCPIX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.36% | 1.22% | +0.14% |
Volatility (6M)Calculated over the trailing 6-month period | 2.88% | 2.66% | +0.22% |
Volatility (1Y)Calculated over the trailing 1-year period | 3.95% | 3.52% | +0.43% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.41% | 5.68% | +0.73% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 5.17% | 5.68% | -0.51% |
WFBIX vs. VCPIX - Expense Ratio Comparison
WFBIX has a 0.05% expense ratio, which is lower than VCPIX's 0.30% expense ratio.
Dividends
WFBIX vs. VCPIX - Dividend Comparison
WFBIX's dividend yield for the trailing twelve months is around 3.91%, less than VCPIX's 4.74% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
VCPIX Vanguard Core-Plus Bond Fund Investor Shares | 4.74% | 4.76% | 5.08% | 4.46% | 3.15% | 0.25% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% |
WFBIX iShares U.S. Aggregate Bond Index Fund | 3.91% | 3.78% | 3.68% | 6.82% | 2.60% | 2.04% | 2.43% | 2.88% | 2.71% | 2.24% | 2.25% | 2.20% |
Frequently Asked Questions
With a correlation of 0.93, WFBIX and VCPIX 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.
WFBIX has higher volatility (1.36%) compared to VCPIX (1.22%). In terms of maximum drawdown, WFBIX dropped -18.68% vs VCPIX's -17.33%.
VCPIX currently has the higher Sharpe Ratio (1.58 vs 1.25), 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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