MUB vs. FMBIX

Last updated Apr 2, 2026

Compare and contrast key facts about iShares National AMT-Free Muni Bond ETF (MUB) and Fidelity Municipal Bond Index Fund (FMBIX).

MUB is a passively managed fund by iShares that tracks the performance of the S&P National AMT-Free Municipal Bond Index. It was launched on Sep 7, 2007. FMBIX is managed by Fidelity. It was launched on Jul 11, 2019.

Performance

MUB vs. FMBIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares National AMT-Free Muni Bond ETF (MUB) and Fidelity Municipal Bond Index Fund (FMBIX). The values are adjusted to include any dividend payments, if applicable.

MUB vs. FMBIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019
MUB iShares National AMT-Free Muni Bond ETF	0.04%	3.78%	1.26%	5.56%	-7.34%	1.02%	5.12%	1.62%
FMBIX Fidelity Municipal Bond Index Fund	0.00%	0.60%	1.32%	5.89%	-10.00%	1.14%	3.10%	1.48%

Returns By Period

MUB

• 1D: 0.42%
• 1M: -1.55%
• YTD: 0.04%
• 6M: 1.52%
• 1Y: 4.03%
• 3Y*: 2.67%
• 5Y*: 0.88%
• 10Y*: 2.00%

FMBIX

• 1D: —
• 1M: —
• YTD: —
• 6M: —
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

MUB vs. FMBIX - Expense Ratio Comparison

Both MUB and FMBIX have an expense ratio of 0.07%, making them cost-effective options compared to the broader market, where average expense ratios typically range from 0.3% to 0.9%.

MUB

iShares National AMT-Free Muni Bond ETF

FMBIX

Fidelity Municipal Bond Index Fund

Return for Risk

MUB vs. FMBIX — Risk / Return Rank

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

MUB

MUB Risk / Return Rank: 49
MUB Sharpe Ratio Rank: 52
MUB Sortino Ratio Rank: 44
MUB Omega Ratio Rank: 55
MUB Calmar Ratio Rank: 49
MUB Martin Ratio Rank: 43

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.

MUB vs. FMBIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares National AMT-Free Muni Bond ETF (MUB) and Fidelity Municipal Bond Index Fund (FMBIX). 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.

	MUB	FMBIX	Difference
Sharpe ratio Return per unit of total volatility	0.98	—	—
Sortino ratio Return per unit of downside risk	1.27	—	—
Omega ratio Gain probability vs. loss probability	1.21	—	—
Calmar ratio Return relative to maximum drawdown	1.33	—	—
Martin ratio Return relative to average drawdown	4.22	—	—
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

Sharpe Ratios by Period

	MUB	FMBIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.98	—	—
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.22	—	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.41	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.58	—	—

Correlation

The correlation between MUB and FMBIX is 0.63, which is considered to be moderate. This suggests that the two assets have some degree of positive relationship in their price movements. Moderate correlation can be acceptable for portfolio diversification, offering a balance between risk and potential returns.

Dividends

MUB vs. FMBIX - Dividend Comparison

MUB's dividend yield for the trailing twelve months is around 3.19%, while FMBIX has not paid dividends to shareholders.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MUB iShares National AMT-Free Muni Bond ETF	3.19%	3.14%	3.01%	2.65%	2.11%	1.81%	2.11%	2.42%	2.46%	2.26%	2.21%	2.51%
FMBIX Fidelity Municipal Bond Index Fund	0.00%	0.70%	2.60%	2.29%	1.17%	1.28%	1.59%	0.77%	0.00%	0.00%	0.00%	0.00%

Drawdowns

Drawdown Indicators

	MUB	FMBIX	Difference
Max Drawdown Largest peak-to-trough decline	-13.68%	—	—
Max Drawdown (1Y) Largest decline over 1 year	-3.30%	—	—
Max Drawdown (5Y) Largest decline over 5 years	-11.88%	—	—
Max Drawdown (10Y) Largest decline over 10 years	-13.68%	—	—
Current Drawdown Current decline from peak	-1.87%	—	—
Average Drawdown Average peak-to-trough decline	-2.24%	—	—
Ulcer Index Depth and duration of drawdowns from previous peaks	1.04%	—	—

Volatility

Volatility by Period

	MUB	FMBIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.56%	—	—
Volatility (6M) Calculated over the trailing 6-month period	2.07%	—	—
Volatility (1Y) Calculated over the trailing 1-year period	4.15%	—	—
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.04%	—	—
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.91%	—	—