BDBKX vs. BASMX

Last updated Jun 3, 2026

BDBKX (iShares Russell 2000 Small-Cap Index Fund Class K) and BASMX (iShares Total U.S. Stock Market Index Fund Investor A Shares) are both mutual funds - BDBKX is a Small Cap Blend Equities fund tracking the Russell 2000 Index, while BASMX is a Large Cap Blend Equities fund tracking the Russell 3000 Index. Both are passively managed. Over the past 10 years, BDBKX returned 11.08%/yr vs 14.76%/yr for BASMX. Their correlation of 0.86 suggests significant overlap in exposure. BDBKX charges 0.07%/yr vs 0.33%/yr for BASMX.

Performance

BDBKX vs. BASMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares Russell 2000 Small-Cap Index Fund Class K (BDBKX) and iShares Total U.S. Stock Market Index Fund Investor A Shares (BASMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BDBKX achieves a 17.58% return, which is significantly higher than BASMX's 11.34% return. Over the past 10 years, BDBKX has underperformed BASMX with an annualized return of 11.08%, while BASMX has yielded a comparatively higher 14.76% annualized return.

BDBKX

• 1D: -0.47%
• 1M: 3.41%
• YTD: 17.58%
• 6M: 18.53%
• 1Y: 42.04%
• 3Y*: 18.23%
• 5Y*: 6.23%
• 10Y*: 11.08%

BASMX

• 1D: 0.23%
• 1M: 5.00%
• YTD: 11.34%
• 6M: 11.67%
• 1Y: 28.86%
• 3Y*: 21.84%
• 5Y*: 12.64%
• 10Y*: 14.76%

*Multi-year figures are annualized to reflect compound growth (CAGR)

BDBKX vs. BASMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BDBKX iShares Russell 2000 Small-Cap Index Fund Class K	17.58%	12.81%	11.40%	17.04%	-20.32%	14.59%	20.02%	25.66%	-11.01%	14.71%
BASMX iShares Total U.S. Stock Market Index Fund Investor A Shares	11.34%	16.81%	23.46%	25.63%	-19.32%	25.26%	20.37%	30.71%	-5.57%	20.65%

Correlation

The correlation between BDBKX and BASMX is 0.84, 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	0.84
Correlation (3Y) Calculated over the trailing 3-year period	0.83
Correlation (5Y) Calculated over the trailing 5-year period	0.86
Correlation (10Y) Calculated over the trailing 10-year period	0.86
Correlation (All Time) Calculated using the full available price history since Jan 5, 2016	0.86

The correlation between BDBKX and BASMX has been stable across timeframes, ranging from 0.83 to 0.86 - a consistent structural relationship.

Return for Risk

BDBKX vs. BASMX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

BDBKX

BDBKX Risk / Return Rank: 62
BDBKX Sharpe Ratio Rank: 57
BDBKX Sortino Ratio Rank: 53
BDBKX Omega Ratio Rank: 46
BDBKX Calmar Ratio Rank: 82
BDBKX Martin Ratio Rank: 71

BASMX

BASMX Risk / Return Rank: 69
BASMX Sharpe Ratio Rank: 69
BASMX Sortino Ratio Rank: 62
BASMX Omega Ratio Rank: 61
BASMX Calmar Ratio Rank: 71
BASMX Martin Ratio Rank: 81

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

BDBKX vs. BASMX - 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 Total U.S. Stock Market Index Fund Investor A Shares (BASMX). 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.

	BDBKX	BASMX	Difference
Sharpe ratio Return per unit of total volatility	2.23	2.43	-0.20
Sortino ratio Return per unit of downside risk	3.07	3.31	-0.24
Omega ratio Gain probability vs. loss probability	1.37	1.44	-0.07
Calmar ratio Return relative to maximum drawdown	3.81	3.29	+0.52
Martin ratio Return relative to average drawdown	13.56	15.12	-1.57
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BDBKX vs. BASMX - Sharpe Ratio Comparison

The current BDBKX Sharpe Ratio is 2.23, which is comparable to the BASMX Sharpe Ratio of 2.43. The chart below compares the historical Sharpe Ratios of BDBKX and BASMX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	BDBKX	BASMX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.23	2.43	-0.20
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.27	0.73	-0.46
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.47	0.80	-0.34
Sharpe Ratio (All Time) Calculated using the full available price history	0.43	0.81	-0.37

Drawdowns

BDBKX vs. BASMX - Drawdown Comparison

The maximum BDBKX drawdown since its inception was -41.66%, which is greater than BASMX's maximum drawdown of -34.95%. Use the drawdown chart below to compare losses from any high point for BDBKX and BASMX.

Drawdown Indicators

	BDBKX	BASMX	Difference
Max Drawdown Largest peak-to-trough decline	-41.66%	-34.95%	-6.71%
Max Drawdown (1Y) Largest decline over 1 year	-10.97%	-8.92%	-2.05%
Max Drawdown (3Y) Largest decline over 3 years	-27.53%	-19.32%	-8.21%
Max Drawdown (5Y) Largest decline over 5 years	-31.96%	-25.12%	-6.84%
Max Drawdown (10Y) Largest decline over 10 years	-41.66%	-34.95%	-6.71%
Current Drawdown Current decline from peak	-1.04%	0.00%	-1.04%
Average Drawdown Average peak-to-trough decline	-8.75%	-4.59%	-4.16%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.08%	1.94%	+1.14%

Volatility

BDBKX vs. BASMX - Volatility Comparison

iShares Russell 2000 Small-Cap Index Fund Class K (BDBKX) has a higher volatility of 5.52% compared to iShares Total U.S. Stock Market Index Fund Investor A Shares (BASMX) at 2.94%. This indicates that BDBKX's price experiences larger fluctuations and is considered to be riskier than BASMX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BDBKX	BASMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.52%	2.94%	+2.58%
Volatility (6M) Calculated over the trailing 6-month period	13.54%	9.16%	+4.38%
Volatility (1Y) Calculated over the trailing 1-year period	19.11%	12.16%	+6.95%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	23.16%	17.38%	+5.78%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	23.71%	18.41%	+5.30%

BDBKX vs. BASMX - Expense Ratio Comparison

BDBKX has a 0.07% expense ratio, which is lower than BASMX's 0.33% expense ratio.

Dividends

BDBKX vs. BASMX - Dividend Comparison

BDBKX's dividend yield for the trailing twelve months is around 2.70%, more than BASMX's 0.78% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BASMX iShares Total U.S. Stock Market Index Fund Investor A Shares	0.78%	0.86%	0.99%	1.19%	1.33%	1.33%	1.20%	1.90%	2.18%	1.93%	1.37%	0.00%
BDBKX iShares Russell 2000 Small-Cap Index Fund Class K	2.70%	3.17%	4.84%	2.96%	1.76%	7.67%	1.45%	3.47%	4.29%	3.18%	4.62%	3.64%

Frequently Asked Questions

Can I hold both BDBKX and BASMX in my portfolio?

BDBKX and BASMX have a correlation of 0.84, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BDBKX or BASMX?

BDBKX has higher volatility (5.52%) compared to BASMX (2.94%). In terms of maximum drawdown, BDBKX dropped -41.66% vs BASMX's -34.95%.

Which has better risk-adjusted returns?

BASMX currently has the higher Sharpe Ratio (2.43 vs 2.23), 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.