NPHIX vs. PIAMX

Last updated Jun 5, 2026

NPHIX (American Century High Income Fund) and PIAMX (PIA High Yield (MACS) Fund) are both High Yield Bonds funds. Over the past 5 years, NPHIX returned 3.46%/yr vs 4.10%/yr for PIAMX. A 0.72 correlation means they provide meaningful diversification when combined. NPHIX charges 0.58%/yr vs 0.20%/yr for PIAMX.

Performance

NPHIX vs. PIAMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century High Income Fund (NPHIX) and PIA High Yield (MACS) Fund (PIAMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, NPHIX achieves a 1.32% return, which is significantly higher than PIAMX's 0.79% return.

NPHIX

• 1D: -0.23%
• 1M: 0.10%
• YTD: 1.32%
• 6M: 1.88%
• 1Y: 7.20%
• 3Y*: 8.22%
• 5Y*: 3.46%
• 10Y*: 5.46%

PIAMX

• 1D: 0.00%
• 1M: 0.71%
• YTD: 0.79%
• 6M: 1.23%
• 1Y: 3.70%
• 3Y*: 7.53%
• 5Y*: 4.10%
• 10Y*: —

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

NPHIX vs. PIAMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018
NPHIX American Century High Income Fund	1.32%	8.86%	6.92%	12.05%	-12.59%	6.12%	8.03%	12.70%	-2.49%
PIAMX PIA High Yield (MACS) Fund	0.79%	2.34%	11.23%	16.38%	-10.93%	7.82%	9.05%	11.77%	-2.63%

Correlation

The correlation between NPHIX and PIAMX is 0.66, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.66
Correlation (3Y) Calculated over the trailing 3-year period	0.69
Correlation (5Y) Calculated over the trailing 5-year period	0.74
Correlation (All Time) Calculated using the full available price history since Jan 30, 2018	0.72

The correlation between NPHIX and PIAMX has been stable across timeframes, ranging from 0.66 to 0.74 - a consistent structural relationship.

Return for Risk

NPHIX vs. PIAMX — Risk / Return Rank

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

NPHIX

NPHIX Risk / Return Rank: 72
NPHIX Sharpe Ratio Rank: 59
NPHIX Sortino Ratio Rank: 81
NPHIX Omega Ratio Rank: 78
NPHIX Calmar Ratio Rank: 63
NPHIX Martin Ratio Rank: 82

PIAMX

PIAMX Risk / Return Rank: 17
PIAMX Sharpe Ratio Rank: 20
PIAMX Sortino Ratio Rank: 17
PIAMX Omega Ratio Rank: 24
PIAMX Calmar Ratio Rank: 11
PIAMX Martin Ratio Rank: 11

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.

NPHIX vs. PIAMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century High Income Fund (NPHIX) and PIA High Yield (MACS) Fund (PIAMX). 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.

	NPHIX	PIAMX	Difference
Sharpe ratio: Return per unit of total volatility	2.21	1.27	+0.94
Sortino ratio: Return per unit of downside risk	3.82	1.73	+2.09
Omega ratio: Gain probability vs. loss probability	1.50	1.26	+0.25
Calmar ratio: Return relative to maximum drawdown	2.96	1.06	+1.91
Martin ratio: Return relative to average drawdown	14.91	3.17	+11.74
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

NPHIX vs. PIAMX - Sharpe Ratio Comparison

The current NPHIX Sharpe Ratio is 2.21, which is higher than the PIAMX Sharpe Ratio of 1.27. The chart below compares the historical Sharpe Ratios of NPHIX and PIAMX, 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

	NPHIX	PIAMX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.21	1.27	+0.94
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.66	1.02	-0.36
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.97	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	1.00	1.22	-0.23

Drawdowns

NPHIX vs. PIAMX - Drawdown Comparison

The maximum NPHIX drawdown since its inception was -21.67%, which is greater than PIAMX's maximum drawdown of -18.15%. Use the drawdown chart below to compare losses from any high point for NPHIX and PIAMX.

Drawdown Indicators

	NPHIX	PIAMX	Difference
Max Drawdown Largest peak-to-trough decline	-21.67%	-18.15%	-3.52%
Max Drawdown (1Y) Largest decline over 1 year	-2.52%	-3.75%	+1.23%
Max Drawdown (3Y) Largest decline over 3 years	-3.94%	-6.17%	+2.23%
Max Drawdown (5Y) Largest decline over 5 years	-16.34%	-13.92%	-2.42%
Max Drawdown (10Y) Largest decline over 10 years	-21.67%	—	—
Current Drawdown Current decline from peak	-0.23%	-0.55%	+0.32%
Average Drawdown Average peak-to-trough decline	-2.52%	-2.34%	-0.18%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.50%	1.25%	-0.75%

Volatility

NPHIX vs. PIAMX - Volatility Comparison

American Century High Income Fund (NPHIX) has a higher volatility of 1.11% compared to PIA High Yield (MACS) Fund (PIAMX) at 0.68%. This indicates that NPHIX's price experiences larger fluctuations and is considered to be riskier than PIAMX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	NPHIX	PIAMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.11%	0.68%	+0.43%
Volatility (6M) Calculated over the trailing 6-month period	2.54%	2.43%	+0.11%
Volatility (1Y) Calculated over the trailing 1-year period	3.38%	3.12%	+0.26%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.28%	4.04%	+1.24%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.65%	4.23%	+1.42%

NPHIX vs. PIAMX - Expense Ratio Comparison

NPHIX has a 0.58% expense ratio, which is higher than PIAMX's 0.20% expense ratio.

Dividends

NPHIX vs. PIAMX - Dividend Comparison

NPHIX's dividend yield for the trailing twelve months is around 6.76%, less than PIAMX's 7.90% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
NPHIX American Century High Income Fund	6.76%	6.69%	6.07%	4.81%	4.95%	5.77%	5.35%	5.54%	6.24%	5.87%	5.72%	7.44%
PIAMX PIA High Yield (MACS) Fund	7.90%	9.12%	8.49%	8.12%	7.99%	8.64%	6.63%	6.96%	7.14%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both NPHIX and PIAMX in my portfolio?

NPHIX and PIAMX have a correlation of 0.66, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, NPHIX or PIAMX?

NPHIX has higher volatility (1.11%) compared to PIAMX (0.68%). In terms of maximum drawdown, NPHIX dropped -21.67% vs PIAMX's -18.15%.

Which has better risk-adjusted returns?

NPHIX currently has the higher Sharpe Ratio (2.21 vs 1.27), 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.