BDBKX vs. BSPAX
BDBKX (iShares Russell 2000 Small-Cap Index Fund Class K) and BSPAX (iShares S&P 500 Index Fund Investor A Shares) are both mutual funds - BDBKX is a Small Cap Blend Equities fund tracking the Russell 2000 Index, while BSPAX is a S&P 500 fund tracking the S&P 500 Index. Both are passively managed. Over the past 10 years, BDBKX returned 10.93%/yr vs 14.86%/yr for BSPAX. Their correlation of 0.82 means they have usually moved in the same direction. BDBKX charges 0.07%/yr vs 0.35%/yr for BSPAX.
Performance
BDBKX vs. BSPAX - Performance Comparison
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Returns By Period
In the year-to-date period, BDBKX achieves a 23.05% return, which is significantly higher than BSPAX's 13.52% return. Over the past 10 years, BDBKX has underperformed BSPAX with an annualized return of 10.93%, while BSPAX has yielded a comparatively higher 14.86% annualized return.
BDBKX
- 1D
- 1.86%
- 1M
- 0.97%
- 6M
- 16.28%
- YTD
- 23.05%
- 1Y
- 38.01%
- 3Y*
- 17.31%
- 5Y*
- 7.76%
- 10Y*
- 10.93%
- ALL TIME*
- 10.09%
BSPAX
- 1D
- 1.79%
- 1M
- 2.67%
- 6M
- 12.85%
- YTD
- 13.52%
- 1Y
- 23.81%
- 3Y*
- 21.15%
- 5Y*
- 13.01%
- 10Y*
- 14.86%
- ALL TIME*
- 13.60%
Liquidity Comparison
| Position | Avg. Volume Value (2W) | Avg. Volume Value (1M) | Avg. Volume Value (3M) |
|---|---|---|---|
| $0.00 | $0.00 | $0.00 | |
| $0.00 | $0.00 | $0.00 |
BDBKX vs. BSPAX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
BDBKX iShares Russell 2000 Small-Cap Index Fund Class K | 23.05% | 12.81% | 11.40% | 17.04% | -20.32% | 14.59% | 20.02% | 25.66% | -11.01% | 14.71% |
BSPAX iShares S&P 500 Index Fund Investor A Shares | 13.52% | 17.46% | 24.54% | 25.85% | -18.40% | 28.22% | 18.05% | 31.02% | -5.05% | 20.97% |
Correlation
The correlation between BDBKX and BSPAX is 0.79, which is moderate. They have sometimes moved together and sometimes differently, sharing some price drivers without tracking each other closely.
| Correlation | |
|---|---|
Correlation (1Y) Focuses on recent behavior, but can change the most. | 0.79 |
Correlation (3Y) Balances recent behavior with more history. | 0.78 |
Correlation (5Y) Shows whether the relationship held over a longer period. | 0.82 |
Correlation (10Y) Provides a long-term view across more market conditions. | 0.81 |
Correlation (All Time) Calculated using the full available price history since Jan 2, 2014 | 0.82 |
The correlation between BDBKX and BSPAX has been stable across timeframes, ranging from 0.78 to 0.82 - a consistent structural relationship.
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Return for Risk
BDBKX vs. BSPAX — Risk / Return Rank
BDBKX
BSPAX
BDBKX vs. BSPAX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares Russell 2000 Small-Cap Index Fund Class K (BDBKX) and iShares S&P 500 Index Fund Investor A Shares (BSPAX). 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.
| BDBKX | BSPAX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | +0.21 | ||
| Sortino ratioReturn per unit of downside risk | +0.34 | ||
| Omega ratioGain probability vs. loss probability | 1.34 | 1.33 | +0.01 |
| Calmar ratioReturn relative to maximum drawdown | 3.56 | 2.60 | +0.95 |
| Martin ratioReturn relative to average drawdown | 12.62 | 11.15 | +1.47 |
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Drawdowns
BDBKX vs. BSPAX - Drawdown Comparison
The maximum BDBKX drawdown since its inception was -41.66%, which is greater than BSPAX's maximum drawdown of -33.76%. Use the drawdown chart below to compare losses from any high point for BDBKX and BSPAX.
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Drawdown Indicators
| BDBKX | BSPAX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -41.66% | -33.76% | -7.90% |
Max Drawdown (1Y)Largest decline over 1 year | -10.97% | -8.95% | -2.02% |
Max Drawdown (3Y)Largest decline over 3 years | -27.53% | -18.77% | -8.76% |
Max Drawdown (5Y)Largest decline over 5 years | -31.96% | -24.70% | -7.26% |
Max Drawdown (10Y)Largest decline over 10 years | -41.66% | -33.76% | -7.90% |
Current DrawdownCurrent decline from peak | 0.00% | 0.00% | 0.00% |
Average DrawdownAverage peak-to-trough decline | -8.66% | -3.96% | -4.70% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 3.09% | 2.09% | +1.00% |
Volatility
BDBKX vs. BSPAX - Volatility Comparison
iShares Russell 2000 Small-Cap Index Fund Class K (BDBKX) has a higher volatility of 4.57% compared to iShares S&P 500 Index Fund Investor A Shares (BSPAX) at 4.13%. This indicates that BDBKX's price experiences larger fluctuations and is considered to be riskier than BSPAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| BDBKX | BSPAX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 4.57% | 4.13% | +0.44% |
Volatility (6M)Calculated over the trailing 6-month period | 14.19% | 10.32% | +3.87% |
Volatility (1Y)Calculated over the trailing 1-year period | 19.36% | 12.94% | +6.42% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 23.15% | 17.02% | +6.13% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 23.69% | 18.05% | +5.64% |
BDBKX vs. BSPAX - Expense Ratio Comparison
BDBKX has a 0.07% expense ratio, which is lower than BSPAX's 0.35% expense ratio.
Dividends
BDBKX vs. BSPAX - Dividend Comparison
BDBKX's dividend yield for the trailing twelve months is around 2.65%, more than BSPAX's 1.32% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
BDBKX iShares Russell 2000 Small-Cap Index Fund Class K | 2.65% | 3.17% | 4.84% | 2.96% | 1.76% | 7.67% | 1.45% | 3.47% | 4.29% | 3.18% | 4.62% | 3.64% |
BSPAX iShares S&P 500 Index Fund Investor A Shares | 1.32% | 1.43% | 1.12% | 1.22% | 1.67% | 1.52% | 1.37% | 1.70% | 1.74% | 1.40% | 1.62% | 2.17% |
Frequently Asked Questions
BDBKX and BSPAX have a correlation of 0.79, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
BDBKX has higher volatility (4.57%) compared to BSPAX (4.13%). In terms of maximum drawdown, BDBKX dropped -41.66% vs BSPAX's -33.76%.
BDBKX currently has the higher Sharpe Ratio (2.03 vs 1.81), 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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