FMUB vs MFLX: Grades, Fees and Holdings Compared

Fidelity Municipal Bond Opportunities ETF

FMUBANasdaq

First Trust Flexible Municipal High Income ETF

MFLXCNasdaq

Overlap

No data

Expense ratio

FMUB −0.19pt a year

FMUB0.30%MFLX0.49%

Avg volume · 30D

FMUB 16.8×the volume

FMUB103KMFLX6.12K

FMUB vs MFLX Performance

Nov 7, 2025 – Nov 9, 2026

+2.4%FMUB+1.8%MFLX

Expense ratio: FMUB 0.30%, better; MFLX 0.49%
Fund size: FMUB $362M; MFLX $20M
1Y total return: FMUB +2.4%, better; MFLX +1.8%
Yield (12M): FMUB 3.53%; MFLX 4.35%, better
Holdings: FMUB 721; MFLX 77
Avg volume (30D): FMUB 103K sh, better; MFLX 6.12K sh
NAV per share: FMUB $50.39; MFLX $16.69
52W range

ETF.net Grade

Pillar letters and Scores for FMUB, MFLX, with each pillar’s weight
Pillar	FMUB	MFLX
Cost30% weight	A100Higher	D31
Mission25% weight	A89Higher	A78
Risk15% weight	B69Higher	C45
Tradability15% weight	C45Higher	F8
Holdings10% weight	F16	D34Higher
Durability5% weight	C50	C52Higher

Rank among High-Yield Municipal Bonds funds

How we build Categories ›

Same Category. FMUB and MFLX are both graded against the same 18 High-Yield Municipal Bonds funds, so their Grades compare head to head.

High-Yield Municipal Bonds⁠

Category · 18 funds

See all 18 ›

FMUB ranks 3rd and MFLX 17th of 18 funds in the High-Yield Municipal Bonds Category.

Rank 1ACGHMCapital Group Municipal High-Income ETFScore 81
Rank 2AHYDVanEck High Yield Muni ETFScore 79
Rank 3AFMUBFidelity Municipal Bond Opportunities ETFScore 73
Rank 4AHYMBState Street SPDR Nuveen ICE High Yield Municipal Bond ETFScore 71
Rank 16CFCALFirst Trust California Municipal High Income ETFScore 49
Rank 17CMFLXFirst Trust Flexible Municipal High Income ETFScore 42
Rank 18DFMNYFirst Trust New York Municipal High Income ETFScore 37

Our read on each fund

ETF.net Research

FMUBAFidelity Municipal Bond Opportunities ETF

MFLXCFirst Trust Flexible Municipal High Income ETF

In short

FMUB Tax-free income is the job, but the mandate also leaves room for capital growth. Fidelity's 2023-vintage muni fund spreads across roughly 400 bonds and pays monthly.

MFLX Launched in 2016 as a basket of closed-end muni funds, MFLX was rebuilt in 2022 into a hands-on portfolio of roughly 80 high-yield munis, with closed-end-style leverage available through tender option bond trusts.

Stated mandate

FMUB The fund seeks high current income exempt from federal income tax, with capital growth also considered.

MFLX The Fund seeks current income by investing at least 80% of its net assets in municipal debt securities whose interest is exempt from regular federal income taxes.

Why people hold it

FMUB The mandate is broader than the usual muni playbook: high current income exempt from federal income tax, with capital growth also considered.
It does what the label says. The portfolio hews closely to its stated muni-income mandate, one of the tighter mandate matches among municipal bond ETFs.
Roughly 400 bonds behind it, and the payout runs monthly rather than quarterly.

MFLX Go-anywhere active mandate: any maturity, duration or credit quality, with a stated tilt toward longer, higher-yielding bonds rated below investment grade or unrated.sec.gov
The 80% federally tax-exempt policy is fundamental, meaning First Trust cannot change it without a shareholder vote.ftportfolios.com
A roughly 80-bond portfolio that pays monthly, concentrated enough that individual credit calls move the needle.
Can borrow through tender option bond trusts and hold the inverse floaters: closed-end-fund plumbing inside an ETF wrapper.sec.gov

Worth knowing

FMUB At 0.30%, the fee sits right at the muni-ETF median. Index-tracking staples like VTEB (0.03%) and MUB (0.05%) charge a fraction of that.
It trades thinly next to the category's giants, which can mean wider spreads at the moment you place an order.
Launched in 2023, so the track record is short and assets stay modest against the multi-billion-dollar muni index funds.

MFLX At 0.49%, it charges above the category median of 19 funds, and above index-based peers HYD (0.32%) and HYMB (0.35%).
Leverage plus a long-duration, lower-rated tilt cuts both ways: price swings can run sharper than a plain investment-grade muni fund's.sec.gov
It stays small and trades lightly, so spreads can be wider than in the category's heavyweights.

Full FMUB profile⁠

Full MFLX profile⁠

FMUB vs MFLX Holdings

How FMUB and MFLX differ

No overlap figure

Two bond funds rarely hold the same issues.

Level by level

Countryby domicile98.8%
Asset classBonds100%
Sector1 Sector100%

Sector

Sector weights in FMUB and MFLX, widest gap first
Sector	More in FMUBMore in MFLX	Gap	FMUB	MFLX
Municipal		Same weight	100.0%	100.0%

Country, concentration and asset class

Country by domicile

Country weights in FMUB and MFLX, widest gap first
Country	More in FMUBMore in MFLX	Gap	FMUB	MFLX
United States		FMUB +1.2 points	100.0%	98.8%
Puerto Rico		MFLX +1.2 points	0.0%	1.2%

Concentration

Weight in the 10 largest Holdings

FMUB27.7%
MFLX19.5%

Securities held

FMUB710
MFLX76

Asset class

FMUB: Bonds
MFLX: Bonds

Holdings

Two bond funds rarely hold the same issues, so this page lists no shared Holdings. FMUB holds 710 securities, MFLX 76.

All 388 FMUB holdings⁠All 76 MFLX holdings⁠

How we measure overlap

Each holding counts at its smaller weight in the two funds, summed over the full Holdings. Sector, country and asset class use the same rule on each fund’s split. Cash, FX and derivative lines stay out of the counts. Two bond funds get no overlap figure.

FMUB vs MFLX Cost

Overpaying MFLX vs FMUB

$3,643

On $10,000 over 30 years. 7% growth a year before fees, expense ratio only.

FMUB 0.30%
$6,149
MFLX 0.49%
$9,792

Amount$10,000

Years30 years

Cost over time

FMUB 0.30%
MFLX 0.49%
Overpaying

Year by year

Year	FMUB	MFLX	Overpaying
10	$545	$883	$338
20	$2,113	$3,394	$1,281
30	$6,149	$9,792	$3,643

Expense ratio

0.30%FMUB, cheaper
0.49%MFLX

FMUB0.30%MFLX0.49%

0.30%0.70%

Middle half of High-Yield Municipal Bonds funds
Median 0.39%

FMUB cheapest of 18 funds

MFLX 13th cheapest of 18 funds

FMUB vs MFLX Dividends

Last 12 months to Nov 9, 2026

Yield (12M): FMUB 3.53%; MFLX 4.35%, better
Payout (12M): FMUB $1.79; MFLX $0.72
Last payment: FMUB $0.12; MFLX $0.06
Ex-dividend: FMUB Oct 29, 2026; MFLX Oct 21, 2026
Paid on: FMUB Nov 2, 2026; MFLX Oct 30, 2026
Frequency: FMUB Monthly; MFLX Monthly

Distribution history

Per share, 2023 to 2026, same scale for both

FMUBMonthly · 20 paymentsAll FMUB payments⁠

MFLXMonthly · 46 paymentsAll MFLX payments⁠

FMUB vs MFLX Risk

Fall from peak · 5 years

This chart needs five years of history for both funds.

Risk facts

VolatilityStd dev, 3 years: FMUB 5.4%since May 2025MFLX 7.2%
Return per unit of riskSharpe ratio, 3 years: FMUB 0.04since May 2025MFLX 0.21
Worst fallMax drawdown, 5 years: FMUB −6.1%since Apr 2025MFLX −25.1%
Market sensitivityBeta, 5 years: FMUB 0.91MFLX 1.14; Market = 1

Popular comparisons

FMUBAvsCGHMA
Fidelity Municipal Bond Opportunities ETF · Capital Group Municipal High-Income ETF
Expense ratio
0.30% · 0.34%
Category
MFLXCvsCGHMA
First Trust Flexible Municipal High Income ETF · Capital Group Municipal High-Income ETF
Expense ratio
0.49% · 0.34%
Category
FMUBAvsHYDA
Fidelity Municipal Bond Opportunities ETF · VanEck High Yield Muni ETF
Expense ratio
0.30% · 0.32%
Category
MFLXCvsHYDA
First Trust Flexible Municipal High Income ETF · VanEck High Yield Muni ETF
Expense ratio
0.49% · 0.32%
Category
FMUBAvsHYMBA
Fidelity Municipal Bond Opportunities ETF · State Street SPDR Nuveen ICE High Yield Municipal Bond ETF
Expense ratio
0.30% · 0.35%
Category
MFLXCvsHYMBA
First Trust Flexible Municipal High Income ETF · State Street SPDR Nuveen ICE High Yield Municipal Bond ETF
Expense ratio
0.49% · 0.35%
Category