MFSM vs. IBMN

Last updated Jun 3, 2026

MFSM (MFS Active Intermediate Muni Bond ETF) and IBMN (iShares iBonds Dec 2025 Term Muni Bond ETF) are both Municipal Bonds funds. MFSM is actively managed, while IBMN is passively managed. Over the past year, MFSM returned 7.56% vs 1.26% for IBMN. At a 0.12 correlation, their price movements are largely independent. MFSM charges 0.34%/yr vs 0.18%/yr for IBMN.

Performance

MFSM vs. IBMN - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Active Intermediate Muni Bond ETF (MFSM) and iShares iBonds Dec 2025 Term Muni Bond ETF (IBMN). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

MFSM

• 1D: 0.11%
• 1M: 0.64%
• YTD: 1.76%
• 6M: 2.32%
• 1Y: 7.56%
• 3Y*: —
• 5Y*: —
• 10Y*: —

IBMN

• 1D: 0.00%
• 1M: 0.00%
• YTD: 0.00%
• 6M: 0.00%
• 1Y: 1.26%
• 3Y*: 2.44%
• 5Y*: 0.51%
• 10Y*: —

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

MFSM vs. IBMN - Yearly Performance Comparison

	2026 (YTD)	2025	2024
MFSM MFS Active Intermediate Muni Bond ETF	1.76%	5.25%	-1.30%
IBMN iShares iBonds Dec 2025 Term Muni Bond ETF	0.00%	2.49%	0.10%

Correlation

The correlation between MFSM and IBMN is 0.09, meaning there is essentially no relationship between their price movements. Each responds to its own set of market drivers, making them strong candidates for combining in a diversified portfolio.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.09
Correlation (All Time) Calculated using the full available price history since Dec 6, 2024	0.12

Return for Risk

MFSM vs. IBMN — Risk / Return Rank

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

MFSM

MFSM Risk / Return Rank: 76
MFSM Sharpe Ratio Rank: 85
MFSM Sortino Ratio Rank: 90
MFSM Omega Ratio Rank: 91
MFSM Calmar Ratio Rank: 55
MFSM Martin Ratio Rank: 58

IBMN

IBMN Risk / Return Rank: 71
IBMN Sharpe Ratio Rank: 66
IBMN Sortino Ratio Rank: 81
IBMN Omega Ratio Rank: 94
IBMN Calmar Ratio Rank: 32
IBMN Martin Ratio Rank: 82

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.

MFSM vs. IBMN - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Active Intermediate Muni Bond ETF (MFSM) and iShares iBonds Dec 2025 Term Muni Bond ETF (IBMN). 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.

	MFSM	IBMN	Difference
Sharpe ratio Return per unit of total volatility	2.84	2.22	+0.63
Sortino ratio Return per unit of downside risk	4.35	3.67	+0.67
Omega ratio Gain probability vs. loss probability	1.62	1.69	-0.08
Calmar ratio Return relative to maximum drawdown	2.80	1.58	+1.22
Martin ratio Return relative to average drawdown	10.40	16.58	-6.18
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MFSM vs. IBMN - Sharpe Ratio Comparison

The current MFSM Sharpe Ratio is 2.84, which is comparable to the IBMN Sharpe Ratio of 2.22. The chart below compares the historical Sharpe Ratios of MFSM and IBMN, 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

	MFSM	IBMN	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.84	2.22	+0.63
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	0.30	—
Sharpe Ratio (All Time) Calculated using the full available price history	1.12	0.58	+0.53

Drawdowns

MFSM vs. IBMN - Drawdown Comparison

The maximum MFSM drawdown since its inception was -3.86%, smaller than the maximum IBMN drawdown of -12.40%. Use the drawdown chart below to compare losses from any high point for MFSM and IBMN.

Drawdown Indicators

	MFSM	IBMN	Difference
Max Drawdown Largest peak-to-trough decline	-3.86%	-12.40%	+8.54%
Max Drawdown (1Y) Largest decline over 1 year	-2.65%	-0.25%	-2.40%
Max Drawdown (3Y) Largest decline over 3 years	—	-1.10%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-7.36%	—
Current Drawdown Current decline from peak	-0.49%	-0.05%	-0.44%
Average Drawdown Average peak-to-trough decline	-0.88%	-1.81%	+0.93%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.71%	0.10%	+0.61%

Volatility

MFSM vs. IBMN - Volatility Comparison

MFS Active Intermediate Muni Bond ETF (MFSM) has a higher volatility of 0.93% compared to iShares iBonds Dec 2025 Term Muni Bond ETF (IBMN) at 0.00%. This indicates that MFSM's price experiences larger fluctuations and is considered to be riskier than IBMN based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MFSM	IBMN	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.93%	0.00%	+0.93%
Volatility (6M) Calculated over the trailing 6-month period	1.97%	0.50%	+1.47%
Volatility (1Y) Calculated over the trailing 1-year period	2.67%	0.71%	+1.96%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	3.45%	1.80%	+1.65%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	3.45%	3.89%	-0.44%

MFSM vs. IBMN - Expense Ratio Comparison

MFSM has a 0.34% expense ratio, which is higher than IBMN's 0.18% expense ratio.

Dividends

MFSM vs. IBMN - Dividend Comparison

MFSM's dividend yield for the trailing twelve months is around 3.55%, more than IBMN's 1.14% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018
IBMN iShares iBonds Dec 2025 Term Muni Bond ETF	1.14%	2.03%	2.03%	1.72%	0.97%	0.70%	1.11%	1.65%	0.23%
MFSM MFS Active Intermediate Muni Bond ETF	3.55%	3.53%	0.23%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both MFSM and IBMN in my portfolio?

MFSM and IBMN have a correlation of 0.09, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MFSM or IBMN?

MFSM has higher volatility (0.93%) compared to IBMN (0.00%). In terms of maximum drawdown, MFSM dropped -3.86% vs IBMN's -12.40%.

Which ETF is better, MFSM or IBMN?

On 1-year performance, MFSM leads with 7.56% vs 1.26% for IBMN. On fees, IBMN is cheaper at 0.18% per year. On volatility, IBMN has been the lower-risk option at 0.00%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, MFSM or IBMN?

Over the 1-year period, MFSM has performed better with a 7.56% return vs 1.26%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, MFSM or IBMN?

IBMN is cheaper with a 0.18% expense ratio, compared with 0.34% for MFSM.

Which ETF pays a higher dividend yield, MFSM or IBMN?

MFSM has the higher dividend yield at 3.55%, compared with 1.14% for IBMN.

What is the main difference between MFSM and IBMN?

They also come from different issuers: MFS and iShares. Their fees differ too: 0.34% for MFSM and 0.18% for IBMN.

Which has better risk-adjusted returns?

MFSM currently has the higher Sharpe Ratio (2.84 vs 2.22), 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.