SUB vs. THYM

Last updated Jun 23, 2026

SUB (iShares Short-Term National Muni Bond ETF) and THYM (T. Rowe Price High Income Municipal ETF) are both exchange-traded funds - SUB is a Municipal Bonds fund tracking the ICE Short Maturity AMT-Free US National Municipal Index - Benchmark TR Gross, while THYM is a High Yield Muni fund actively managed by T. Rowe Price. SUB is passively managed, while THYM is actively managed. A 0.54 correlation means they provide meaningful diversification when combined. SUB charges 0.07%/yr vs 0.32%/yr for THYM.

Performance

SUB vs. THYM - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares Short-Term National Muni Bond ETF (SUB) 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, SUB achieves a 0.93% return, which is significantly lower than THYM's 3.82% return.

SUB

• 1D: 0.00%
• 1M: 0.52%
• YTD: 0.93%
• 6M: 1.10%
• 1Y: 2.93%
• 3Y*: 3.08%
• 5Y*: 1.51%
• 10Y*: 1.46%

THYM

• 1D: -0.04%
• 1M: 1.89%
• YTD: 3.82%
• 6M: 3.92%
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

SUB vs. THYM - Yearly Performance Comparison

	2026 (YTD)	2025
SUB iShares Short-Term National Muni Bond ETF	0.93%	0.56%
THYM T. Rowe Price High Income Municipal ETF	3.82%	0.25%

Correlation

The correlation between SUB and THYM is 0.54, 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 20, 2025	0.54

Return for Risk

SUB vs. THYM — Risk / Return Rank

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

SUB

SUB Risk / Return Rank: 82
SUB Sharpe Ratio Rank: 90
SUB Sortino Ratio Rank: 92
SUB Omega Ratio Rank: 94
SUB Calmar Ratio Rank: 74
SUB Martin Ratio Rank: 60

THYM

Risk / return metrics aren't available yet — we need at least 12 months of trading data to calculate them.

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.

SUB vs. THYM - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Short-Term National Muni Bond ETF (SUB) 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.

Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.

	SUB	THYM	Difference
Sharpe ratio: Return per unit of total volatility	2.92	—	—
Sortino ratio: Return per unit of downside risk	4.21	—	—
Omega ratio: Gain probability vs. loss probability	1.64	—	—
Calmar ratio: Return relative to maximum drawdown	3.65	—	—
Martin ratio: Return relative to average drawdown	10.32	—	—

Drawdowns

SUB vs. THYM - Drawdown Comparison

The maximum SUB drawdown since its inception was -9.46%, which is greater than THYM's maximum drawdown of -2.93%. Use the drawdown chart below to compare losses from any high point for SUB and THYM.

Drawdown Indicators

	SUB	THYM	Difference
Max Drawdown Largest peak-to-trough decline	-9.46%	-2.93%	-6.53%
Max Drawdown (1Y) Largest decline over 1 year	-0.81%	—	—
Max Drawdown (3Y) Largest decline over 3 years	-1.23%	—	—
Max Drawdown (5Y) Largest decline over 5 years	-4.35%	—	—
Max Drawdown (10Y) Largest decline over 10 years	-9.46%	—	—
Current Drawdown Current decline from peak	0.00%	-0.04%	+0.04%
Average Drawdown Average peak-to-trough decline	-0.91%	-0.47%	-0.44%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.28%	—	—

Volatility

Volatility by Period

	SUB	THYM	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.25%	—	—
Volatility (6M) Calculated over the trailing 6-month period	0.80%	—	—
Volatility (1Y) Calculated over the trailing 1-year period	1.01%	4.31%	-3.30%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	1.64%	4.31%	-2.67%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.60%	4.31%	-1.71%

SUB vs. THYM - Expense Ratio Comparison

SUB has a 0.07% expense ratio, which is lower than THYM's 0.32% expense ratio.

Dividends

SUB vs. THYM - Dividend Comparison

SUB's dividend yield for the trailing twelve months is around 2.52%, more than THYM's 2.17% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
SUB iShares Short-Term National Muni Bond ETF	2.52%	2.42%	2.10%	1.73%	0.86%	0.72%	1.23%	1.58%	1.32%	0.95%	0.75%	0.77%
THYM T. Rowe Price High Income Municipal ETF	2.17%	0.37%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both SUB and THYM in my portfolio?

SUB and THYM have a correlation of 0.54, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which ETF is better, SUB or THYM?

On fees, SUB is cheaper at 0.07% per year. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF is cheaper, SUB or THYM?

SUB is cheaper with a 0.07% expense ratio, compared with 0.32% for THYM.

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

SUB has the higher dividend yield at 2.52%, compared with 2.17% for THYM.

What is the main difference between SUB and THYM?

SUB 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: 0.07% for SUB and 0.32% for THYM.