IBMS vs. THYM

Last updated Jun 4, 2026

IBMS (iShares iBonds Dec 2030 Term Muni Bond ETF) and THYM (T. Rowe Price High Income Municipal ETF) are both exchange-traded funds - IBMS is a Municipal Bonds fund tracking the S&P AMT-Free Municipal Series Callable-Adjusted Dec 2030 Index, while THYM is a High Yield Muni fund actively managed by T. Rowe Price. IBMS is passively managed, while THYM is actively managed. A 0.55 correlation means they provide meaningful diversification when combined. IBMS charges 0.18%/yr vs 0.32%/yr for THYM.

Performance

IBMS vs. THYM - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares iBonds Dec 2030 Term Muni Bond ETF (IBMS) and T. Rowe Price High Income Municipal ETF (THYM). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, IBMS achieves a 0.35% return, which is significantly lower than THYM's 3.33% return.

IBMS

• 1D: 0.02%
• 1M: 0.30%
• YTD: 0.35%
• 6M: 0.87%
• 1Y: 4.50%
• 3Y*: —
• 5Y*: —
• 10Y*: —

THYM

• 1D: 0.14%
• 1M: 1.14%
• YTD: 3.33%
• 6M: 3.62%
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

IBMS vs. THYM - Yearly Performance Comparison

	2026 (YTD)	2025
IBMS iShares iBonds Dec 2030 Term Muni Bond ETF	0.35%	0.72%
THYM T. Rowe Price High Income Municipal ETF	3.33%	0.27%

Correlation

The correlation between IBMS and THYM is 0.55, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (All Time) Calculated using the full available price history since Nov 21, 2025	0.55

Return for Risk

IBMS vs. THYM — Risk / Return Rank

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

IBMS

IBMS Risk / Return Rank: 60
IBMS Sharpe Ratio Rank: 69
IBMS Sortino Ratio Rank: 74
IBMS Omega Ratio Rank: 82
IBMS Calmar Ratio Rank: 41
IBMS Martin Ratio Rank: 36

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.

IBMS vs. THYM - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares iBonds Dec 2030 Term Muni Bond ETF (IBMS) and T. Rowe Price High Income Municipal ETF (THYM). 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.

	IBMS	THYM	Difference
Sharpe ratio: Return per unit of total volatility	2.23	—	—
Sortino ratio: Return per unit of downside risk	3.30	—	—
Omega ratio: Gain probability vs. loss probability	1.48	—	—
Calmar ratio: Return relative to maximum drawdown	2.00	—	—
Martin ratio: Return relative to average drawdown	5.41	—	—
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

	IBMS	THYM	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.23	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	1.42	1.62	-0.20

Drawdowns

IBMS vs. THYM - Drawdown Comparison

The maximum IBMS drawdown since its inception was -3.01%, roughly equal to the maximum THYM drawdown of -2.93%. Use the drawdown chart below to compare losses from any high point for IBMS and THYM.

Drawdown Indicators

	IBMS	THYM	Difference
Max Drawdown Largest peak-to-trough decline	-3.01%	-2.93%	-0.08%
Max Drawdown (1Y) Largest decline over 1 year	-2.25%	—	—
Current Drawdown Current decline from peak	-1.17%	0.00%	-1.17%
Average Drawdown Average peak-to-trough decline	-0.70%	-0.49%	-0.21%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.83%	—	—

Volatility

Volatility by Period

	IBMS	THYM	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.59%	—	—
Volatility (6M) Calculated over the trailing 6-month period	1.43%	—	—
Volatility (1Y) Calculated over the trailing 1-year period	2.03%	4.35%	-2.32%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	3.07%	4.35%	-1.28%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	3.07%	4.35%	-1.28%

IBMS vs. THYM - Expense Ratio Comparison

IBMS has a 0.18% expense ratio, which is lower than THYM's 0.32% expense ratio.

Dividends

IBMS vs. THYM - Dividend Comparison

IBMS's dividend yield for the trailing twelve months is around 2.52%, more than THYM's 2.18% yield.

Position	TTM	2025	2024
IBMS iShares iBonds Dec 2030 Term Muni Bond ETF	2.52%	2.49%	1.38%
THYM T. Rowe Price High Income Municipal ETF	2.18%	0.37%	0.00%

Frequently Asked Questions

Can I hold both IBMS and THYM in my portfolio?

IBMS and THYM have a correlation of 0.55, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which ETF is better, IBMS or THYM?

On fees, IBMS is cheaper at 0.18% per year. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF is cheaper, IBMS or THYM?

IBMS is cheaper with a 0.18% expense ratio, compared with 0.32% for THYM.

Which ETF pays a higher dividend yield, IBMS or THYM?

IBMS has the higher dividend yield at 2.52%, compared with 2.18% for THYM.

What is the main difference between IBMS and THYM?

IBMS is categorized as Municipal Bonds, while THYM is High Yield Muni. They also come from different issuers: iShares and T. Rowe Price. Their fees differ too: 0.18% for IBMS and 0.32% for THYM.