BIDAX vs. DFABX

Last updated Jun 4, 2026

BIDAX (iShares Municipal Bond Index Fund) and DFABX (DFA Short-Term Selective State Municipal Bond Portfolio) are both Municipal Bonds funds. Over the past 3 years, BIDAX returned 3.69%/yr vs 2.82%/yr for DFABX. At a 0.41 correlation, their price movements are largely independent. BIDAX charges 0.50%/yr vs 0.25%/yr for DFABX.

Performance

BIDAX vs. DFABX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares Municipal Bond Index Fund (BIDAX) and DFA Short-Term Selective State Municipal Bond Portfolio (DFABX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BIDAX achieves a 1.41% return, which is significantly higher than DFABX's 0.98% return.

BIDAX

• 1D: 0.18%
• 1M: 0.72%
• YTD: 1.41%
• 6M: 1.76%
• 1Y: 6.97%
• 3Y*: 3.69%
• 5Y*: 0.69%
• 10Y*: —

DFABX

• 1D: 0.00%
• 1M: 0.20%
• YTD: 0.98%
• 6M: 1.10%
• 1Y: 2.66%
• 3Y*: 2.82%
• 5Y*: —
• 10Y*: —

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

BIDAX vs. DFABX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022
BIDAX iShares Municipal Bond Index Fund	1.41%	4.52%	1.44%	5.74%	-1.95%
DFABX DFA Short-Term Selective State Municipal Bond Portfolio	0.98%	2.46%	2.90%	2.87%	0.55%

Correlation

The correlation between BIDAX and DFABX is 0.23, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.23
Correlation (3Y) Calculated over the trailing 3-year period	0.28
Correlation (All Time) Calculated using the full available price history since Apr 18, 2022	0.41

The correlation between BIDAX and DFABX shifts across timeframes, from 0.23 (1 year) to 0.41 (all time), reflecting how their relationship changes across market environments.

Return for Risk

BIDAX vs. DFABX — Risk / Return Rank

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

BIDAX

BIDAX Risk / Return Rank: 67
BIDAX Sharpe Ratio Rank: 80
BIDAX Sortino Ratio Rank: 86
BIDAX Omega Ratio Rank: 90
BIDAX Calmar Ratio Rank: 39
BIDAX Martin Ratio Rank: 36

DFABX

DFABX Risk / Return Rank: 100
DFABX Sharpe Ratio Rank: 99
DFABX Sortino Ratio Rank: 100
DFABX Omega Ratio Rank: 100
DFABX Calmar Ratio Rank: 100
DFABX Martin Ratio Rank: 100

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.

BIDAX vs. DFABX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Municipal Bond Index Fund (BIDAX) and DFA Short-Term Selective State Municipal Bond Portfolio (DFABX). 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.

	BIDAX	DFABX	Difference
Sharpe ratio Return per unit of total volatility	2.63	4.77	-2.14
Sortino ratio Return per unit of downside risk	4.14	12.57	-8.43
Omega ratio Gain probability vs. loss probability	1.66	6.47	-4.81
Calmar ratio Return relative to maximum drawdown	2.37	24.96	-22.58
Martin ratio Return relative to average drawdown	8.02	107.63	-99.62
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BIDAX vs. DFABX - Sharpe Ratio Comparison

The current BIDAX Sharpe Ratio is 2.63, which is lower than the DFABX Sharpe Ratio of 4.77. The chart below compares the historical Sharpe Ratios of BIDAX and DFABX, 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

	BIDAX	DFABX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.63	4.77	-2.14
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.17	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.54	2.48	-1.94

Drawdowns

BIDAX vs. DFABX - Drawdown Comparison

The maximum BIDAX drawdown since its inception was -14.39%, which is greater than DFABX's maximum drawdown of -2.46%. Use the drawdown chart below to compare losses from any high point for BIDAX and DFABX.

Drawdown Indicators

	BIDAX	DFABX	Difference
Max Drawdown Largest peak-to-trough decline	-14.39%	-2.46%	-11.93%
Max Drawdown (1Y) Largest decline over 1 year	-2.95%	-0.11%	-2.84%
Max Drawdown (3Y) Largest decline over 3 years	-6.07%	-0.60%	-5.47%
Max Drawdown (5Y) Largest decline over 5 years	-14.39%	—	—
Current Drawdown Current decline from peak	-0.65%	0.00%	-0.65%
Average Drawdown Average peak-to-trough decline	-3.52%	-0.24%	-3.28%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.87%	0.02%	+0.85%

Volatility

BIDAX vs. DFABX - Volatility Comparison

iShares Municipal Bond Index Fund (BIDAX) has a higher volatility of 1.06% compared to DFA Short-Term Selective State Municipal Bond Portfolio (DFABX) at 0.20%. This indicates that BIDAX's price experiences larger fluctuations and is considered to be riskier than DFABX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BIDAX	DFABX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.06%	0.20%	+0.86%
Volatility (6M) Calculated over the trailing 6-month period	2.06%	0.42%	+1.64%
Volatility (1Y) Calculated over the trailing 1-year period	2.68%	0.56%	+2.12%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.08%	0.96%	+3.12%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.44%	0.96%	+3.48%

BIDAX vs. DFABX - Expense Ratio Comparison

BIDAX has a 0.50% expense ratio, which is higher than DFABX's 0.25% expense ratio.

Dividends

BIDAX vs. DFABX - Dividend Comparison

BIDAX's dividend yield for the trailing twelve months is around 3.11%, more than DFABX's 2.63% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018
BIDAX iShares Municipal Bond Index Fund	3.11%	4.09%	3.25%	2.16%	1.92%	2.36%	2.35%	3.64%	0.48%
DFABX DFA Short-Term Selective State Municipal Bond Portfolio	2.63%	2.33%	2.86%	2.52%	1.25%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both BIDAX and DFABX in my portfolio?

BIDAX and DFABX have a correlation of 0.23, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BIDAX or DFABX?

BIDAX has higher volatility (1.06%) compared to DFABX (0.20%). In terms of maximum drawdown, BIDAX dropped -14.39% vs DFABX's -2.46%.

Which has better risk-adjusted returns?

DFABX currently has the higher Sharpe Ratio (4.77 vs 2.63), 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.