ABHYX vs. AHMFX

Last updated Jun 3, 2026

ABHYX (American Century High-Yield Municipal Fund) and AHMFX (American High-Income Municipal Bond Fund Class F-2) are both High Yield Muni funds. Over the past 10 years, ABHYX returned 2.89%/yr vs 3.46%/yr for AHMFX. Their correlation of 0.86 suggests significant overlap in exposure. ABHYX charges 0.59%/yr vs 0.42%/yr for AHMFX.

Performance

ABHYX vs. AHMFX - Performance Comparison

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

Returns By Period

The year-to-date returns for both investments are quite close, with ABHYX having a 2.03% return and AHMFX slightly higher at 2.13%. Over the past 10 years, ABHYX has underperformed AHMFX with an annualized return of 2.89%, while AHMFX has yielded a comparatively higher 3.46% annualized return.

ABHYX

• 1D: -0.11%
• 1M: 0.69%
• YTD: 2.03%
• 6M: 2.41%
• 1Y: 7.68%
• 3Y*: 5.28%
• 5Y*: 0.83%
• 10Y*: 2.89%

AHMFX

• 1D: 0.00%
• 1M: 0.67%
• YTD: 2.13%
• 6M: 2.70%
• 1Y: 8.36%
• 3Y*: 6.33%
• 5Y*: 1.87%
• 10Y*: 3.46%

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

ABHYX vs. AHMFX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
ABHYX American Century High-Yield Municipal Fund	2.03%	3.77%	6.16%	5.90%	-13.90%	5.61%	4.68%	9.72%	1.48%	9.27%
AHMFX American High-Income Municipal Bond Fund Class F-2	2.13%	6.03%	6.45%	7.04%	-12.44%	5.49%	4.61%	9.12%	1.80%	9.09%

Correlation

The correlation between ABHYX and AHMFX is 0.90, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.90
Correlation (3Y) Calculated over the trailing 3-year period	0.90
Correlation (5Y) Calculated over the trailing 5-year period	0.92
Correlation (10Y) Calculated over the trailing 10-year period	0.89
Correlation (All Time) Calculated using the full available price history since Jan 5, 2009	0.86

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

Return for Risk

ABHYX vs. AHMFX — Risk / Return Rank

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

ABHYX

ABHYX Risk / Return Rank: 57
ABHYX Sharpe Ratio Rank: 54
ABHYX Sortino Ratio Rank: 68
ABHYX Omega Ratio Rank: 79
ABHYX Calmar Ratio Rank: 43
ABHYX Martin Ratio Rank: 39

AHMFX

AHMFX Risk / Return Rank: 75
AHMFX Sharpe Ratio Rank: 82
AHMFX Sortino Ratio Rank: 89
AHMFX Omega Ratio Rank: 89
AHMFX Calmar Ratio Rank: 62
AHMFX Martin Ratio Rank: 54

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.

ABHYX vs. AHMFX - Risk-Adjusted Trends Comparison

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

	ABHYX	AHMFX	Difference
Sharpe ratio Return per unit of total volatility	2.17	2.65	-0.47
Sortino ratio Return per unit of downside risk	3.44	4.32	-0.87
Omega ratio Gain probability vs. loss probability	1.52	1.63	-0.12
Calmar ratio Return relative to maximum drawdown	2.54	3.04	-0.50
Martin ratio Return relative to average drawdown	8.62	10.89	-2.28
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

ABHYX vs. AHMFX - Sharpe Ratio Comparison

The current ABHYX Sharpe Ratio is 2.17, which is comparable to the AHMFX Sharpe Ratio of 2.65. The chart below compares the historical Sharpe Ratios of ABHYX and AHMFX, 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

	ABHYX	AHMFX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.17	2.65	-0.47
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.17	0.39	-0.22
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.58	0.76	-0.18
Sharpe Ratio (All Time) Calculated using the full available price history	1.05	1.54	-0.50

Drawdowns

ABHYX vs. AHMFX - Drawdown Comparison

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

Drawdown Indicators

	ABHYX	AHMFX	Difference
Max Drawdown Largest peak-to-trough decline	-26.34%	-17.65%	-8.69%
Max Drawdown (1Y) Largest decline over 1 year	-3.16%	-2.76%	-0.40%
Max Drawdown (3Y) Largest decline over 3 years	-7.40%	-6.20%	-1.20%
Max Drawdown (5Y) Largest decline over 5 years	-18.54%	-17.65%	-0.89%
Max Drawdown (10Y) Largest decline over 10 years	-18.54%	-17.65%	-0.89%
Current Drawdown Current decline from peak	-0.31%	-0.15%	-0.16%
Average Drawdown Average peak-to-trough decline	-3.11%	-2.37%	-0.74%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.93%	0.77%	+0.16%

Volatility

ABHYX vs. AHMFX - Volatility Comparison

American Century High-Yield Municipal Fund (ABHYX) has a higher volatility of 1.18% compared to American High-Income Municipal Bond Fund Class F-2 (AHMFX) at 1.10%. This indicates that ABHYX's price experiences larger fluctuations and is considered to be riskier than AHMFX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	ABHYX	AHMFX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.18%	1.10%	+0.08%
Volatility (6M) Calculated over the trailing 6-month period	2.47%	2.24%	+0.23%
Volatility (1Y) Calculated over the trailing 1-year period	3.38%	3.06%	+0.32%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.95%	4.86%	+0.09%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.99%	4.55%	+0.44%

ABHYX vs. AHMFX - Expense Ratio Comparison

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

Dividends

ABHYX vs. AHMFX - Dividend Comparison

ABHYX's dividend yield for the trailing twelve months is around 4.33%, more than AHMFX's 4.13% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ABHYX American Century High-Yield Municipal Fund	4.33%	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	4.13%	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 ABHYX and AHMFX in my portfolio?

ABHYX and AHMFX have a correlation of 0.90, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, ABHYX or AHMFX?

ABHYX has higher volatility (1.18%) compared to AHMFX (1.10%). In terms of maximum drawdown, ABHYX dropped -26.34% vs AHMFX's -17.65%.

Which has better risk-adjusted returns?

AHMFX currently has the higher Sharpe Ratio (2.65 vs 2.17), 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.