APOIX vs. PRAIX

Last updated Aug 2, 2026

APOIX (American Century Short Duration Inflation Protection Bond Fund Investor Class) and PRAIX (PIMCO Long-Term Real Return Fund) are both Inflation-Protected Bonds funds. Over the past 10 years, APOIX returned 3.05%/yr vs 0.12%/yr for PRAIX. Their 0.69 correlation means they have sometimes moved together and sometimes differently. APOIX charges 0.57%/yr vs 0.50%/yr for PRAIX.

Performance

APOIX vs. PRAIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century Short Duration Inflation Protection Bond Fund Investor Class (APOIX) and PIMCO Long-Term Real Return Fund (PRAIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, APOIX achieves a 1.67% return, which is significantly higher than PRAIX's -4.47% return. Over the past 10 years, APOIX has outperformed PRAIX with an annualized return of 3.05%, while PRAIX has yielded a comparatively lower 0.12% annualized return.

APOIX

• 1D: 0.00%
• 1M: 0.19%
• 6M: 1.09%
• YTD: 1.67%
• 1Y: 2.60%
• 3Y*: 4.76%
• 5Y*: 2.57%
• 10Y*: 3.05%
• ALL TIME*: 3.04%

PRAIX

• 1D: -0.19%
• 1M: -4.16%
• 6M: -4.06%
• YTD: -4.47%
• 1Y: -2.39%
• 3Y*: -1.85%
• 5Y*: -7.90%
• 10Y*: 0.12%
• ALL TIME*: 4.52%

*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)
APOIX American Century Short Duration Inflation Protection Bond Fund Investor Class	$0.00	$0.00	$0.00
PRAIX PIMCO Long-Term Real Return Fund	$0.00	$0.00	$0.00

APOIX vs. PRAIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
APOIX American Century Short Duration Inflation Protection Bond Fund Investor Class	1.67%	5.95%	4.15%	3.82%	-3.89%	6.30%	5.06%	4.77%	1.81%	0.73%
PRAIX PIMCO Long-Term Real Return Fund	-4.47%	5.26%	-4.11%	0.14%	-33.83%	7.21%	27.16%	19.62%	-6.49%	8.84%

Correlation

The correlation between APOIX and PRAIX is 0.40, which is low. Their historical price movements had little consistent relationship.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.40
Correlation (3Y) Balances recent behavior with more history.	0.61
Correlation (5Y) Shows whether the relationship held over a longer period.	0.61
Correlation (10Y) Provides a long-term view across more market conditions.	0.58
Correlation (All Time) Calculated using the full available price history since May 31, 2005	0.69

Over the past year, the correlation between APOIX and PRAIX has dropped to 0.40 - well below their long-term average of 0.69, suggesting their price drivers have been diverging.

Return for Risk

APOIX vs. PRAIX — Risk / Return Rank

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

APOIX

APOIX Risk / Return Rank: 80
APOIX Sharpe Ratio Rank: 71
APOIX Sortino Ratio Rank: 75
APOIX Omega Ratio Rank: 76
APOIX Calmar Ratio Rank: 92
APOIX Martin Ratio Rank: 84

PRAIX

PRAIX Risk / Return Rank: 3
PRAIX Sharpe Ratio Rank: 3
PRAIX Sortino Ratio Rank: 3
PRAIX Omega Ratio Rank: 3
PRAIX Calmar Ratio Rank: 3
PRAIX Martin Ratio Rank: 3

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.

APOIX vs. PRAIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century Short Duration Inflation Protection Bond Fund Investor Class (APOIX) and PIMCO Long-Term Real Return Fund (PRAIX). 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.

	APOIX	PRAIX	Difference
Sharpe ratio: Return per unit of total volatility	1.67	-0.16	+1.84
Sortino ratio: Return per unit of downside risk	2.57	-0.16	+2.73
Omega ratio: Gain probability vs. loss probability	1.34	0.98	+0.36
Calmar ratio: Return relative to maximum drawdown	3.66	-0.18	+3.83
Martin ratio: Return relative to average drawdown	10.52	-0.38	+10.90

APOIX vs. PRAIX - Sharpe Ratio Comparison

The current APOIX Sharpe Ratio is 1.67, which is higher than the PRAIX Sharpe Ratio of -0.16. The chart below compares the historical Sharpe Ratios of APOIX and PRAIX, 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

APOIX vs. PRAIX - Drawdown Comparison

The maximum APOIX drawdown since its inception was -14.54%, smaller than the maximum PRAIX drawdown of -43.52%. Use the drawdown chart below to compare losses from any high point for APOIX and PRAIX.

Drawdown Indicators

	APOIX	PRAIX	Difference
Max Drawdown Largest peak-to-trough decline	-14.54%	-43.52%	+28.98%
Max Drawdown (1Y) Largest decline over 1 year	-0.82%	-8.27%	+7.45%
Max Drawdown (3Y) Largest decline over 3 years	-1.42%	-13.03%	+11.61%
Max Drawdown (5Y) Largest decline over 5 years	-6.58%	-43.52%	+36.94%
Max Drawdown (10Y) Largest decline over 10 years	-6.58%	-43.52%	+36.94%
Current Drawdown Current decline from peak	-0.35%	-37.14%	+36.79%
Average Drawdown Average peak-to-trough decline	-1.98%	-10.41%	+8.43%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.28%	3.86%	-3.58%

Volatility

APOIX vs. PRAIX - Volatility Comparison

The current volatility for American Century Short Duration Inflation Protection Bond Fund Investor Class (APOIX) is 0.41%, while PIMCO Long-Term Real Return Fund (PRAIX) has a volatility of 2.10%. This indicates that APOIX experiences smaller price fluctuations and is considered to be less risky than PRAIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	APOIX	PRAIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.41%	2.10%	-1.69%
Volatility (6M) Calculated over the trailing 6-month period	1.36%	7.00%	-5.64%
Volatility (1Y) Calculated over the trailing 1-year period	1.80%	9.27%	-7.47%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	3.30%	16.28%	-12.98%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.85%	14.96%	-12.11%

APOIX vs. PRAIX - Expense Ratio Comparison

APOIX has a 0.57% expense ratio, which is higher than PRAIX's 0.50% expense ratio.

Dividends

APOIX vs. PRAIX - Dividend Comparison

APOIX's dividend yield for the trailing twelve months is around 3.53%, less than PRAIX's 6.54% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
APOIX American Century Short Duration Inflation Protection Bond Fund Investor Class	3.53%	3.99%	2.31%	2.78%	5.63%	3.92%	0.81%	1.69%	3.99%	1.52%	0.42%	0.00%
PRAIX PIMCO Long-Term Real Return Fund	6.54%	5.72%	4.64%	4.75%	12.40%	15.85%	37.88%	7.20%	3.06%	2.76%	1.54%	2.05%

Frequently Asked Questions

Can I hold both APOIX and PRAIX in my portfolio?

APOIX and PRAIX have a correlation of 0.40, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, APOIX or PRAIX?

PRAIX has higher volatility (2.10%) compared to APOIX (0.41%). In terms of maximum drawdown, APOIX dropped -14.54% vs PRAIX's -43.52%.

Which has better risk-adjusted returns?

APOIX currently has the higher Sharpe Ratio (1.67 vs -0.16), 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.