CATF vs. ZTAX

Last updated Jun 24, 2026

CATF (American Century California Municipal Bond ETF) and ZTAX (X-Square Municipal Income Tax Free ETF) are both Municipal Bonds funds. Both are actively managed. Over the past year, CATF returned 7.60% vs 7.61% for ZTAX. At a correlation of -0.02, they often move in opposite directions. CATF charges 0.27%/yr vs 1.14%/yr for ZTAX.

Performance

CATF vs. ZTAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century California Municipal Bond ETF (CATF) and X-Square Municipal Income Tax Free ETF (ZTAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, CATF achieves a 2.29% return, which is significantly lower than ZTAX's 3.16% return.

CATF

• 1D: -0.08%
• 1M: 1.47%
• YTD: 2.29%
• 6M: 2.24%
• 1Y: 7.60%
• 3Y*: —
• 5Y*: —
• 10Y*: —

ZTAX

• 1D: 0.00%
• 1M: 2.70%
• YTD: 3.16%
• 6M: -1.79%
• 1Y: 7.61%
• 3Y*: 4.78%
• 5Y*: —
• 10Y*: —

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

CATF vs. ZTAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024
CATF American Century California Municipal Bond ETF	2.29%	3.78%	0.62%
ZTAX X-Square Municipal Income Tax Free ETF	3.16%	-1.02%	5.33%

Correlation

The correlation between CATF and ZTAX is -0.12, meaning they tend to move in opposite directions. This is especially valuable for risk management - when one declines, the other has historically tended to hold steady or rise.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	-0.12
Correlation (All Time) Calculated using the full available price history since Jul 18, 2024	-0.02

The correlation between CATF and ZTAX shifts across timeframes, from -0.12 (1 year) to -0.02 (all time), reflecting how their relationship changes across market environments.

Return for Risk

CATF vs. ZTAX — Risk / Return Rank

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

CATF

CATF Risk / Return Rank: 77
CATF Sharpe Ratio Rank: 85
CATF Sortino Ratio Rank: 90
CATF Omega Ratio Rank: 90
CATF Calmar Ratio Rank: 61
CATF Martin Ratio Rank: 59

ZTAX

ZTAX Risk / Return Rank: 15
ZTAX Sharpe Ratio Rank: 12
ZTAX Sortino Ratio Rank: 13
ZTAX Omega Ratio Rank: 16
ZTAX Calmar Ratio Rank: 17
ZTAX Martin Ratio Rank: 17

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. ZTAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century California Municipal Bond ETF (CATF) and X-Square Municipal Income Tax Free ETF (ZTAX). 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.

	CATF	ZTAX	Difference
Sharpe ratio: Return per unit of total volatility	2.49	0.24	+2.25
Sortino ratio: Return per unit of downside risk	3.78	0.58	+3.20
Omega ratio: Gain probability vs. loss probability	1.52	1.10	+0.42
Calmar ratio: Return relative to maximum drawdown	2.76	0.70	+2.06
Martin ratio: Return relative to average drawdown	9.61	1.69	+7.93

CATF vs. ZTAX - Sharpe Ratio Comparison

The current CATF Sharpe Ratio is 2.49, which is higher than the ZTAX Sharpe Ratio of 0.24. The chart below compares the historical Sharpe Ratios of CATF and ZTAX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

CATF vs. ZTAX - Drawdown Comparison

The maximum CATF drawdown since its inception was -4.83%, smaller than the maximum ZTAX drawdown of -15.33%. Use the drawdown chart below to compare losses from any high point for CATF and ZTAX.

Drawdown Indicators

	CATF	ZTAX	Difference
Max Drawdown Largest peak-to-trough decline	-4.83%	-15.33%	+10.50%
Max Drawdown (1Y) Largest decline over 1 year	-2.77%	-10.99%	+8.22%
Max Drawdown (3Y) Largest decline over 3 years	—	-15.33%	—
Current Drawdown Current decline from peak	-0.22%	-9.42%	+9.20%
Average Drawdown Average peak-to-trough decline	-1.24%	-6.82%	+5.58%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.79%	4.52%	-3.73%

Volatility

CATF vs. ZTAX - Volatility Comparison

The current volatility for American Century California Municipal Bond ETF (CATF) is 0.80%, while X-Square Municipal Income Tax Free ETF (ZTAX) has a volatility of 19.58%. This indicates that CATF experiences smaller price fluctuations and is considered to be less risky than ZTAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	CATF	ZTAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.80%	19.58%	-18.78%
Volatility (6M) Calculated over the trailing 6-month period	2.22%	28.24%	-26.02%
Volatility (1Y) Calculated over the trailing 1-year period	3.07%	32.31%	-29.24%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.28%	28.90%	-24.62%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.28%	28.90%	-24.62%

CATF vs. ZTAX - Expense Ratio Comparison

CATF has a 0.27% expense ratio, which is lower than ZTAX's 1.14% expense ratio.

Dividends

CATF vs. ZTAX - Dividend Comparison

CATF's dividend yield for the trailing twelve months is around 3.49%, less than ZTAX's 4.43% yield.

Position	TTM	2025	2024	2023
CATF American Century California Municipal Bond ETF	3.49%	3.40%	1.32%	0.00%
ZTAX X-Square Municipal Income Tax Free ETF	4.43%	4.58%	4.55%	2.14%

Frequently Asked Questions

Can I hold both CATF and ZTAX in my portfolio?

CATF and ZTAX have a correlation of -0.12, 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 ZTAX?

ZTAX has higher volatility (19.58%) compared to CATF (0.80%). In terms of maximum drawdown, CATF dropped -4.83% vs ZTAX's -15.33%.

Which ETF is better, CATF or ZTAX?

On 1-year performance, ZTAX leads with 7.61% vs 7.60% for CATF. On fees, CATF is cheaper at 0.27% per year. On volatility, CATF has been the lower-risk option at 0.80%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, CATF or ZTAX?

Over the 1-year period, ZTAX has performed better with a 7.61% return vs 7.60%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, CATF or ZTAX?

CATF is cheaper with a 0.27% expense ratio, compared with 1.14% for ZTAX.

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

ZTAX has the higher dividend yield at 4.43%, compared with 3.49% for CATF.

What is the main difference between CATF and ZTAX?

They also come from different issuers: American Century and X-Square. Their fees differ too: 0.27% for CATF and 1.14% for ZTAX.

Which has better risk-adjusted returns?

CATF currently has the higher Sharpe Ratio (2.49 vs 0.24), 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.