AHMFX vs. ABHYX

Last updated Aug 1, 2026

AHMFX (American High-Income Municipal Bond Fund Class F-2) and ABHYX (American Century High-Yield Municipal Fund) are both High Yield Muni funds. Over the past 10 years, AHMFX returned 3.20%/yr vs 2.61%/yr for ABHYX. Their correlation of 0.86 means they have usually moved in the same direction. AHMFX charges 0.42%/yr vs 0.59%/yr for ABHYX.

Performance

AHMFX vs. ABHYX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American High-Income Municipal Bond Fund Class F-2 (AHMFX) and American Century High-Yield Municipal Fund (ABHYX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, AHMFX achieves a 1.46% return, which is significantly higher than ABHYX's 1.21% return. Over the past 10 years, AHMFX has outperformed ABHYX with an annualized return of 3.20%, while ABHYX has yielded a comparatively lower 2.61% annualized return.

AHMFX

• 1D: -0.26%
• 1M: -1.87%
• 6M: 0.80%
• YTD: 1.46%
• 1Y: 6.67%
• 3Y*: 5.66%
• 5Y*: 1.40%
• 10Y*: 3.20%
• ALL TIME*: 5.94%

ABHYX

• 1D: -0.35%
• 1M: -2.15%
• 6M: 0.61%
• YTD: 1.21%
• 1Y: 6.52%
• 3Y*: 4.69%
• 5Y*: 0.30%
• 10Y*: 2.61%
• ALL TIME*: 4.10%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
ABHYX American Century High-Yield Municipal Fund	$0.00	$0.00	$0.00
AHMFX American High-Income Municipal Bond Fund Class F-2	$0.00	$0.00	$0.00

AHMFX vs. ABHYX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
AHMFX American High-Income Municipal Bond Fund Class F-2	1.46%	6.03%	6.45%	7.04%	-12.44%	5.49%	4.61%	9.12%	1.80%	9.09%
ABHYX American Century High-Yield Municipal Fund	1.21%	3.77%	6.16%	5.90%	-13.90%	5.61%	4.68%	9.72%	1.48%	9.27%

Correlation

The correlation between AHMFX and ABHYX is 0.89, meaning they have usually moved in the same direction, including during past declines.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.89
Correlation (3Y) Balances recent behavior with more history.	0.90
Correlation (5Y) Shows whether the relationship held over a longer period.	0.92
Correlation (10Y) Provides a long-term view across more market conditions.	0.89
Correlation (All Time) Calculated using the full available price history since Jan 2, 2009	0.86

The correlation between AHMFX and ABHYX has been stable across timeframes, ranging from 0.86 to 0.92 - a consistent structural relationship.

Return for Risk

AHMFX vs. ABHYX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

AHMFX

AHMFX Risk / Return Rank: 90
AHMFX Sharpe Ratio Rank: 95
AHMFX Sortino Ratio Rank: 95
AHMFX Omega Ratio Rank: 95
AHMFX Calmar Ratio Rank: 84
AHMFX Martin Ratio Rank: 80

ABHYX

ABHYX Risk / Return Rank: 83
ABHYX Sharpe Ratio Rank: 90
ABHYX Sortino Ratio Rank: 91
ABHYX Omega Ratio Rank: 93
ABHYX Calmar Ratio Rank: 75
ABHYX Martin Ratio Rank: 68

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

AHMFX vs. ABHYX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American High-Income Municipal Bond Fund Class F-2 (AHMFX) and American Century High-Yield Municipal Fund (ABHYX). 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.

	AHMFX	ABHYX	Difference
Sharpe ratio: Return per unit of total volatility	2.55	2.27	+0.28
Sortino ratio: Return per unit of downside risk	3.99	3.48	+0.51
Omega ratio: Gain probability vs. loss probability	1.60	1.55	+0.05
Calmar ratio: Return relative to maximum drawdown	2.84	2.41	+0.43
Martin ratio: Return relative to average drawdown	9.92	8.39	+1.54

AHMFX vs. ABHYX - Sharpe Ratio Comparison

The current AHMFX Sharpe Ratio is 2.55, which is comparable to the ABHYX Sharpe Ratio of 2.27. The chart below compares the historical Sharpe Ratios of AHMFX and ABHYX, 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

AHMFX vs. ABHYX - Drawdown Comparison

The maximum AHMFX drawdown since its inception was -17.65%, smaller than the maximum ABHYX drawdown of -26.34%. Use the drawdown chart below to compare losses from any high point for AHMFX and ABHYX.

Drawdown Indicators

	AHMFX	ABHYX	Difference
Max Drawdown Largest peak-to-trough decline	-17.65%	-26.34%	+8.69%
Max Drawdown (1Y) Largest decline over 1 year	-2.76%	-3.16%	+0.40%
Max Drawdown (3Y) Largest decline over 3 years	-5.68%	-6.60%	+0.92%
Max Drawdown (5Y) Largest decline over 5 years	-17.65%	-18.54%	+0.89%
Max Drawdown (10Y) Largest decline over 10 years	-17.65%	-18.54%	+0.89%
Current Drawdown Current decline from peak	-1.87%	-2.15%	+0.28%
Average Drawdown Average peak-to-trough decline	-2.35%	-3.10%	+0.75%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.79%	0.90%	-0.11%

Volatility

AHMFX vs. ABHYX - Volatility Comparison

The current volatility for American High-Income Municipal Bond Fund Class F-2 (AHMFX) is 0.92%, while American Century High-Yield Municipal Fund (ABHYX) has a volatility of 1.06%. This indicates that AHMFX experiences smaller price fluctuations and is considered to be less risky than ABHYX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	AHMFX	ABHYX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.92%	1.06%	-0.14%
Volatility (6M) Calculated over the trailing 6-month period	2.38%	2.60%	-0.22%
Volatility (1Y) Calculated over the trailing 1-year period	3.07%	3.35%	-0.28%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.88%	4.97%	-0.09%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.55%	4.99%	-0.44%

AHMFX vs. ABHYX - Expense Ratio Comparison

AHMFX has a 0.42% expense ratio, which is lower than ABHYX's 0.59% expense ratio.

Dividends

AHMFX vs. ABHYX - Dividend Comparison

AHMFX's dividend yield for the trailing twelve months is around 3.81%, less than ABHYX's 4.00% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ABHYX American Century High-Yield Municipal Fund	4.00%	5.11%	4.96%	4.02%	2.77%	3.50%	3.35%	4.08%	3.90%	3.61%	3.61%	3.91%
AHMFX American High-Income Municipal Bond Fund Class F-2	3.81%	5.58%	4.04%	2.97%	2.71%	3.44%	3.60%	3.68%	3.88%	4.19%	3.74%	4.19%

Frequently Asked Questions

Can I hold both AHMFX and ABHYX in my portfolio?

AHMFX and ABHYX have a correlation of 0.89, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, AHMFX or ABHYX?

ABHYX has higher volatility (1.06%) compared to AHMFX (0.92%). In terms of maximum drawdown, AHMFX dropped -17.65% vs ABHYX's -26.34%.

Which has better risk-adjusted returns?

AHMFX currently has the higher Sharpe Ratio (2.55 vs 2.27), 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.