WFSPX vs. BBSOX
WFSPX (iShares S&P 500 Index Fund Class K) and BBSOX (BlackRock Short Obligations Fund) are both mutual funds - WFSPX is a S&P 500 fund tracking the S&P 500 Index, while BBSOX is a Ultrashort Bond fund managed by BlackRock. Over the past 10 years, WFSPX returned 15.68%/yr vs 2.46%/yr for BBSOX. At a 0.00 correlation, their price movements are largely independent. WFSPX charges 0.03%/yr vs 0.30%/yr for BBSOX.
Performance
WFSPX vs. BBSOX - Performance Comparison
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Returns By Period
In the year-to-date period, WFSPX achieves a 9.77% return, which is significantly higher than BBSOX's 1.39% return. Over the past 10 years, WFSPX has outperformed BBSOX with an annualized return of 15.68%, while BBSOX has yielded a comparatively lower 2.46% annualized return.
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%
BBSOX
- 1D
- 0.00%
- 1M
- 0.34%
- YTD
- 1.39%
- 6M
- 1.75%
- 1Y
- 4.14%
- 3Y*
- 4.74%
- 5Y*
- 3.25%
- 10Y*
- 2.46%
WFSPX vs. BBSOX - 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% |
BBSOX BlackRock Short Obligations Fund | 1.39% | 4.74% | 5.36% | 4.36% | 0.60% | -0.10% | 1.54% | 3.01% | 1.96% | 1.18% |
Correlation
The correlation between WFSPX and BBSOX is 0.13, which is low. Their price movements are largely independent, making them effective diversification partners.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.13 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.05 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.06 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.02 |
Correlation (All Time) Calculated using the full available price history since Jan 2, 2013 | 0.00 |
The correlation between WFSPX and BBSOX shifts across timeframes, from 0.00 (all time) to 0.13 (1 year), reflecting how their relationship changes across market environments.
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Return for Risk
WFSPX vs. BBSOX — Risk / Return Rank
WFSPX
BBSOX
WFSPX vs. BBSOX - 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 BlackRock Short Obligations Fund (BBSOX). 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 | BBSOX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.96 | ||
| Sortino ratioReturn per unit of downside risk | -8.08 | ||
| Omega ratioGain probability vs. loss probability | 1.39 | 3.93 | -2.54 |
| Calmar ratioReturn relative to maximum drawdown | 3.01 | 20.97 | -17.96 |
| Martin ratioReturn relative to average drawdown | 13.58 | 67.13 | -53.54 |
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Drawdowns
WFSPX vs. BBSOX - Drawdown Comparison
The maximum WFSPX drawdown since its inception was -58.21%, which is greater than BBSOX's maximum drawdown of -1.59%. Use the drawdown chart below to compare losses from any high point for WFSPX and BBSOX.
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Drawdown Indicators
| WFSPX | BBSOX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -58.21% | -1.59% | -56.62% |
Max Drawdown (1Y)Largest decline over 1 year | -8.90% | -0.20% | -8.70% |
Max Drawdown (3Y)Largest decline over 3 years | -18.74% | -0.30% | -18.44% |
Max Drawdown (5Y)Largest decline over 5 years | -24.51% | -1.00% | -23.51% |
Max Drawdown (10Y)Largest decline over 10 years | -33.74% | -1.59% | -32.15% |
Current DrawdownCurrent decline from peak | -1.72% | -0.10% | -1.62% |
Average DrawdownAverage peak-to-trough decline | -12.76% | -0.08% | -12.68% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 1.97% | 0.06% | +1.91% |
Volatility
WFSPX vs. BBSOX - Volatility Comparison
iShares S&P 500 Index Fund Class K (WFSPX) has a higher volatility of 4.67% compared to BlackRock Short Obligations Fund (BBSOX) at 0.44%. This indicates that WFSPX's price experiences larger fluctuations and is considered to be riskier than BBSOX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| WFSPX | BBSOX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 4.67% | 0.44% | +4.23% |
Volatility (6M)Calculated over the trailing 6-month period | 9.83% | 0.90% | +8.93% |
Volatility (1Y)Calculated over the trailing 1-year period | 12.49% | 1.34% | +11.15% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 16.97% | 1.26% | +15.71% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 18.07% | 1.03% | +17.04% |
WFSPX vs. BBSOX - Expense Ratio Comparison
WFSPX has a 0.03% expense ratio, which is lower than BBSOX's 0.30% expense ratio.
Dividends
WFSPX vs. BBSOX - Dividend Comparison
WFSPX's dividend yield for the trailing twelve months is around 1.59%, less than BBSOX's 4.25% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
BBSOX BlackRock Short Obligations Fund | 4.25% | 4.43% | 5.01% | 3.35% | 1.29% | 0.30% | 1.13% | 2.56% | 2.24% | 1.17% | 1.03% | 0.62% |
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
WFSPX and BBSOX have a correlation of 0.13, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
WFSPX has higher volatility (4.67%) compared to BBSOX (0.44%). In terms of maximum drawdown, WFSPX dropped -58.21% vs BBSOX's -1.59%.
BBSOX currently has the higher Sharpe Ratio (3.11 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.
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