WFBIX vs. SPY
Compare and contrast key facts about iShares U.S. Aggregate Bond Index Fund (WFBIX) and State Street SPDR S&P 500 ETF (SPY).
WFBIX is managed by BlackRock. It was launched on Jul 2, 1993. SPY is a passively managed fund by State Street that tracks the performance of the S&P 500 Index. It was launched on Jan 22, 1993.
Performance
WFBIX vs. SPY - Performance Comparison
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WFBIX vs. SPY - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
WFBIX iShares U.S. Aggregate Bond Index Fund | -0.24% | 7.16% | 1.43% | 9.65% | -13.03% | -1.79% | 7.40% | 8.72% | -0.08% | 3.39% |
SPY State Street SPDR S&P 500 ETF | -3.65% | 17.72% | 24.89% | 26.18% | -18.18% | 28.73% | 18.33% | 31.22% | -4.57% | 21.71% |
Returns By Period
In the year-to-date period, WFBIX achieves a -0.24% return, which is significantly higher than SPY's -3.65% return. Over the past 10 years, WFBIX has underperformed SPY with an annualized return of 2.00%, while SPY has yielded a comparatively higher 14.06% annualized return.
WFBIX
- 1D
- 0.22%
- 1M
- -1.62%
- YTD
- -0.24%
- 6M
- 0.51%
- 1Y
- 3.70%
- 3Y*
- 4.82%
- 5Y*
- 0.96%
- 10Y*
- 2.00%
SPY
- 1D
- 0.75%
- 1M
- -4.28%
- YTD
- -3.65%
- 6M
- -1.42%
- 1Y
- 18.14%
- 3Y*
- 18.48%
- 5Y*
- 11.86%
- 10Y*
- 14.06%
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WFBIX vs. SPY - Expense Ratio Comparison
WFBIX has a 0.05% expense ratio, which is lower than SPY's 0.09% 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%.
Return for Risk
WFBIX vs. SPY — Risk / Return Rank
WFBIX
SPY
WFBIX vs. SPY - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares U.S. Aggregate Bond Index Fund (WFBIX) and State Street SPDR S&P 500 ETF (SPY). 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.
| WFBIX | SPY | Difference | |
|---|---|---|---|
Sharpe ratioReturn per unit of total volatility | 0.92 | 0.96 | -0.03 |
Sortino ratioReturn per unit of downside risk | 1.32 | 1.49 | -0.18 |
Omega ratioGain probability vs. loss probability | 1.16 | 1.23 | -0.07 |
Calmar ratioReturn relative to maximum drawdown | 1.60 | 1.53 | +0.07 |
Martin ratioReturn relative to average drawdown | 4.49 | 7.27 | -2.78 |
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
| WFBIX | SPY | Difference | |
|---|---|---|---|
Sharpe Ratio (1Y)Calculated over the trailing 1-year period | 0.92 | 0.96 | -0.03 |
Sharpe Ratio (5Y)Calculated over the trailing 5-year period | 0.15 | 0.70 | -0.55 |
Sharpe Ratio (10Y)Calculated over the trailing 10-year period | 0.39 | 0.79 | -0.40 |
Sharpe Ratio (All Time)Calculated using the full available price history | 0.94 | 0.56 | +0.38 |
Correlation
The correlation between WFBIX and SPY is -0.07. This indicates that the assets' prices tend to move in opposite directions. Negative correlation can be particularly beneficial for diversification and risk management, as one asset may offset the losses of the other during market fluctuations.
Dividends
WFBIX vs. SPY - Dividend Comparison
WFBIX's dividend yield for the trailing twelve months is around 3.53%, more than SPY's 1.13% yield.
| TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
WFBIX iShares U.S. Aggregate Bond Index Fund | 3.53% | 3.78% | 3.68% | 6.82% | 2.60% | 2.04% | 2.43% | 2.88% | 2.71% | 2.24% | 2.25% | 2.20% |
SPY State Street SPDR S&P 500 ETF | 1.13% | 1.07% | 1.21% | 1.40% | 1.65% | 1.20% | 1.52% | 1.75% | 2.04% | 1.80% | 2.03% | 2.06% |
Drawdowns
WFBIX vs. SPY - Drawdown Comparison
The maximum WFBIX drawdown since its inception was -18.68%, smaller than the maximum SPY drawdown of -55.19%. Use the drawdown chart below to compare losses from any high point for WFBIX and SPY.
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Drawdown Indicators
| WFBIX | SPY | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -18.68% | -55.19% | +36.51% |
Max Drawdown (1Y)Largest decline over 1 year | -2.80% | -12.05% | +9.25% |
Max Drawdown (5Y)Largest decline over 5 years | -17.84% | -24.50% | +6.66% |
Max Drawdown (10Y)Largest decline over 10 years | -18.68% | -33.72% | +15.04% |
Current DrawdownCurrent decline from peak | -2.15% | -5.53% | +3.38% |
Average DrawdownAverage peak-to-trough decline | -2.27% | -9.09% | +6.82% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 1.00% | 2.54% | -1.54% |
Volatility
WFBIX vs. SPY - Volatility Comparison
The current volatility for iShares U.S. Aggregate Bond Index Fund (WFBIX) is 1.55%, while State Street SPDR S&P 500 ETF (SPY) has a volatility of 5.35%. This indicates that WFBIX experiences smaller price fluctuations and is considered to be less risky than SPY based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| WFBIX | SPY | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.55% | 5.35% | -3.80% |
Volatility (6M)Calculated over the trailing 6-month period | 2.59% | 9.50% | -6.91% |
Volatility (1Y)Calculated over the trailing 1-year period | 4.42% | 19.06% | -14.64% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.37% | 17.06% | -10.69% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 5.15% | 17.92% | -12.77% |