WIA vs. APOIX

Last updated Jun 5, 2026

WIA (Western Asset Inflation-Linked Income Fund) and APOIX (American Century Short Duration Inflation Protection Bond Fund Investor Class) are both Inflation-Protected Bonds funds. Over the past 10 years, WIA returned 3.78%/yr vs 3.13%/yr for APOIX. At a 0.26 correlation, their price movements are largely independent. WIA charges 4.00%/yr vs 0.57%/yr for APOIX.

Performance

WIA vs. APOIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Western Asset Inflation-Linked Income Fund (WIA) and American Century Short Duration Inflation Protection Bond Fund Investor Class (APOIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, WIA achieves a 1.36% return, which is significantly lower than APOIX's 2.02% return. Over the past 10 years, WIA has outperformed APOIX with an annualized return of 3.78%, while APOIX has yielded a comparatively lower 3.13% annualized return.

WIA

• 1D: 0.00%
• 1M: 0.27%
• YTD: 1.36%
• 6M: 1.63%
• 1Y: 6.79%
• 3Y*: 7.49%
• 5Y*: -0.48%
• 10Y*: 3.78%

APOIX

• 1D: 0.00%
• 1M: 0.19%
• YTD: 2.02%
• 6M: 1.90%
• 1Y: 4.31%
• 3Y*: 4.85%
• 5Y*: 2.93%
• 10Y*: 3.13%

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

WIA vs. APOIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
WIA Western Asset Inflation-Linked Income Fund	1.36%	11.43%	6.08%	5.04%	-25.85%	7.70%	19.35%	18.98%	-6.83%	6.41%
APOIX American Century Short Duration Inflation Protection Bond Fund Investor Class	2.02%	5.95%	4.15%	3.82%	-3.89%	6.30%	5.06%	4.77%	1.81%	0.73%

Correlation

The correlation between WIA and APOIX is 0.21, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.21
Correlation (3Y) Calculated over the trailing 3-year period	0.43
Correlation (5Y) Calculated over the trailing 5-year period	0.44
Correlation (10Y) Calculated over the trailing 10-year period	0.34
Correlation (All Time) Calculated using the full available price history since Jun 1, 2005	0.26

The correlation between WIA and APOIX shifts across timeframes, from 0.21 (1 year) to 0.44 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

WIA vs. APOIX — Risk / Return Rank

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

WIA

WIA Risk / Return Rank: 19
WIA Sharpe Ratio Rank: 17
WIA Sortino Ratio Rank: 18
WIA Omega Ratio Rank: 18
WIA Calmar Ratio Rank: 24
WIA Martin Ratio Rank: 19

APOIX

APOIX Risk / Return Rank: 86
APOIX Sharpe Ratio Rank: 76
APOIX Sortino Ratio Rank: 85
APOIX Omega Ratio Rank: 80
APOIX Calmar Ratio Rank: 95
APOIX Martin Ratio Rank: 93

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.

WIA vs. APOIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Western Asset Inflation-Linked Income Fund (WIA) and American Century Short Duration Inflation Protection Bond Fund Investor Class (APOIX). 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.

	WIA	APOIX	Difference
Sharpe ratio: Return per unit of total volatility	1.13	2.51	-1.39
Sortino ratio: Return per unit of downside risk	1.70	4.10	-2.41
Omega ratio: Gain probability vs. loss probability	1.21	1.53	-0.32
Calmar ratio: Return relative to maximum drawdown	1.73	5.94	-4.21
Martin ratio: Return relative to average drawdown	4.81	19.52	-14.71
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

WIA vs. APOIX - Sharpe Ratio Comparison

The current WIA Sharpe Ratio is 1.13, which is lower than the APOIX Sharpe Ratio of 2.51. The chart below compares the historical Sharpe Ratios of WIA and APOIX, 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

	WIA	APOIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.13	2.51	-1.39
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.05	0.89	-0.94
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.36	1.10	-0.74
Sharpe Ratio (All Time) Calculated using the full available price history	0.29	0.72	-0.43

Drawdowns

WIA vs. APOIX - Drawdown Comparison

The maximum WIA drawdown since its inception was -30.36%, which is greater than APOIX's maximum drawdown of -14.54%. Use the drawdown chart below to compare losses from any high point for WIA and APOIX.

Drawdown Indicators

	WIA	APOIX	Difference
Max Drawdown Largest peak-to-trough decline	-30.36%	-14.54%	-15.82%
Max Drawdown (1Y) Largest decline over 1 year	-3.95%	-0.76%	-3.19%
Max Drawdown (3Y) Largest decline over 3 years	-8.13%	-1.42%	-6.71%
Max Drawdown (5Y) Largest decline over 5 years	-30.36%	-6.58%	-23.78%
Max Drawdown (10Y) Largest decline over 10 years	-30.36%	-6.58%	-23.78%
Current Drawdown Current decline from peak	-7.59%	-0.00%	-7.59%
Average Drawdown Average peak-to-trough decline	-8.72%	-1.99%	-6.73%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.42%	0.23%	+1.19%

Volatility

WIA vs. APOIX - Volatility Comparison

Western Asset Inflation-Linked Income Fund (WIA) has a higher volatility of 1.33% compared to American Century Short Duration Inflation Protection Bond Fund Investor Class (APOIX) at 0.51%. This indicates that WIA's price experiences larger fluctuations and is considered to be riskier than APOIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	WIA	APOIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.33%	0.51%	+0.82%
Volatility (6M) Calculated over the trailing 6-month period	3.80%	1.25%	+2.55%
Volatility (1Y) Calculated over the trailing 1-year period	6.06%	1.80%	+4.26%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	9.75%	3.31%	+6.44%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	10.59%	2.85%	+7.74%

WIA vs. APOIX - Expense Ratio Comparison

WIA has a 4.00% expense ratio, which is higher than APOIX's 0.57% expense ratio.

Dividends

WIA vs. APOIX - Dividend Comparison

WIA's dividend yield for the trailing twelve months is around 7.68%, more than APOIX's 3.91% 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	3.91%	3.99%	2.31%	2.78%	5.63%	3.92%	0.81%	1.69%	3.99%	1.52%	0.42%	0.00%
WIA Western Asset Inflation-Linked Income Fund	7.68%	7.50%	7.50%	11.08%	15.23%	10.65%	5.71%	3.41%	3.91%	3.43%	3.34%	3.63%

Frequently Asked Questions

Can I hold both WIA and APOIX in my portfolio?

WIA and APOIX have a correlation of 0.21, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, WIA or APOIX?

WIA has higher volatility (1.33%) compared to APOIX (0.51%). In terms of maximum drawdown, WIA dropped -30.36% vs APOIX's -14.54%.

Which has better risk-adjusted returns?

APOIX currently has the higher Sharpe Ratio (2.51 vs 1.13), 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.