CATF vs. SUB

Last updated Jun 4, 2026

CATF (American Century California Municipal Bond ETF) and SUB (iShares Short-Term National Muni Bond ETF) are both Municipal Bonds funds. CATF is actively managed, while SUB is passively managed. Over the past year, CATF returned 7.98% vs 3.18% for SUB. A 0.61 correlation means they provide meaningful diversification when combined. CATF charges 0.27%/yr vs 0.07%/yr for SUB.

Performance

CATF vs. SUB - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century California Municipal Bond ETF (CATF) and iShares Short-Term National Muni Bond ETF (SUB). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, CATF achieves a 1.92% return, which is significantly higher than SUB's 0.79% return.

CATF

• 1D: -0.15%
• 1M: 0.55%
• YTD: 1.92%
• 6M: 1.99%
• 1Y: 7.98%
• 3Y*: —
• 5Y*: —
• 10Y*: —

SUB

• 1D: 0.01%
• 1M: 0.32%
• YTD: 0.79%
• 6M: 1.15%
• 1Y: 3.18%
• 3Y*: 3.19%
• 5Y*: 1.46%
• 10Y*: 1.49%

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

CATF vs. SUB - Yearly Performance Comparison

	2026 (YTD)	2025	2024
CATF American Century California Municipal Bond ETF	1.92%	3.78%	0.66%
SUB iShares Short-Term National Muni Bond ETF	0.79%	3.64%	1.53%

Correlation

The correlation between CATF and SUB is 0.46, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.46
Correlation (All Time) Calculated using the full available price history since Jul 19, 2024	0.61

The correlation between CATF and SUB shifts across timeframes, from 0.46 (1 year) to 0.61 (all time), reflecting how their relationship changes across market environments.

Return for Risk

CATF vs. SUB — Risk / Return Rank

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

CATF

CATF Risk / Return Rank: 74
CATF Sharpe Ratio Rank: 79
CATF Sortino Ratio Rank: 87
CATF Omega Ratio Rank: 87
CATF Calmar Ratio Rank: 59
CATF Martin Ratio Rank: 58

SUB

SUB Risk / Return Rank: 83
SUB Sharpe Ratio Rank: 90
SUB Sortino Ratio Rank: 92
SUB Omega Ratio Rank: 95
SUB Calmar Ratio Rank: 77
SUB Martin Ratio Rank: 62

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.

CATF vs. SUB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century California Municipal Bond ETF (CATF) and iShares Short-Term National Muni Bond ETF (SUB). 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.

	CATF	SUB	Difference
Sharpe ratio: Return per unit of total volatility	2.55	3.20	-0.65
Sortino ratio: Return per unit of downside risk	3.89	4.64	-0.74
Omega ratio: Gain probability vs. loss probability	1.54	1.72	-0.18
Calmar ratio: Return relative to maximum drawdown	2.90	3.97	-1.07
Martin ratio: Return relative to average drawdown	10.17	11.24	-1.06
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

CATF vs. SUB - Sharpe Ratio Comparison

The current CATF Sharpe Ratio is 2.55, which is comparable to the SUB Sharpe Ratio of 3.20. The chart below compares the historical Sharpe Ratios of CATF and SUB, 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

	CATF	SUB	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.55	3.20	-0.65
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	0.90	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.57	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.79	0.42	+0.37

Drawdowns

CATF vs. SUB - Drawdown Comparison

The maximum CATF drawdown since its inception was -4.83%, smaller than the maximum SUB drawdown of -9.46%. Use the drawdown chart below to compare losses from any high point for CATF and SUB.

Drawdown Indicators

	CATF	SUB	Difference
Max Drawdown Largest peak-to-trough decline	-4.83%	-9.46%	+4.63%
Max Drawdown (1Y) Largest decline over 1 year	-2.77%	-0.81%	-1.96%
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	-0.58%	-0.11%	-0.47%
Average Drawdown Average peak-to-trough decline	-1.27%	-0.92%	-0.35%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.79%	0.28%	+0.51%

Volatility

CATF vs. SUB - Volatility Comparison

American Century California Municipal Bond ETF (CATF) has a higher volatility of 1.06% compared to iShares Short-Term National Muni Bond ETF (SUB) at 0.28%. This indicates that CATF's price experiences larger fluctuations and is considered to be riskier than SUB based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	CATF	SUB	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.06%	0.28%	+0.78%
Volatility (6M) Calculated over the trailing 6-month period	2.18%	0.79%	+1.39%
Volatility (1Y) Calculated over the trailing 1-year period	3.14%	1.00%	+2.14%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.33%	1.64%	+2.69%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.33%	2.60%	+1.73%

CATF vs. SUB - Expense Ratio Comparison

CATF has a 0.27% expense ratio, which is higher than SUB's 0.07% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

CATF vs. SUB - Dividend Comparison

CATF's dividend yield for the trailing twelve months is around 3.22%, more than SUB's 2.53% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
CATF American Century California Municipal Bond ETF	3.22%	3.40%	1.32%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%
SUB iShares Short-Term National Muni Bond ETF	2.53%	2.42%	2.10%	1.73%	0.86%	0.72%	1.23%	1.58%	1.32%	0.95%	0.75%	0.77%

Frequently Asked Questions

Can I hold both CATF and SUB in my portfolio?

CATF and SUB have a correlation of 0.46, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, CATF or SUB?

CATF has higher volatility (1.06%) compared to SUB (0.28%). In terms of maximum drawdown, CATF dropped -4.83% vs SUB's -9.46%.

Which ETF is better, CATF or SUB?

On 1-year performance, CATF leads with 7.98% vs 3.18% for SUB. On fees, SUB is cheaper at 0.07% per year. On volatility, SUB has been the lower-risk option at 0.28%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, CATF or SUB?

Over the 1-year period, CATF has performed better with a 7.98% return vs 3.18%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, CATF or SUB?

SUB is cheaper with a 0.07% expense ratio, compared with 0.27% for CATF.

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

CATF has the higher dividend yield at 3.22%, compared with 2.53% for SUB.

What is the main difference between CATF and SUB?

They also come from different issuers: American Century and iShares. Their fees differ too: 0.27% for CATF and 0.07% for SUB.

Which has better risk-adjusted returns?

SUB currently has the higher Sharpe Ratio (3.20 vs 2.55), 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.