EIRRX vs. APOIX

Last updated Jun 26, 2026

EIRRX (Eaton Vance Short Duration Inflation-Protected 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, EIRRX returned 3.75%/yr vs 3.02%/yr for APOIX. A 0.76 correlation means they provide meaningful diversification when combined. EIRRX charges 0.64%/yr vs 0.57%/yr for APOIX.

Performance

EIRRX vs. APOIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Eaton Vance Short Duration Inflation-Protected Income Fund (EIRRX) 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, EIRRX achieves a 0.85% return, which is significantly lower than APOIX's 1.28% return. Over the past 10 years, EIRRX has outperformed APOIX with an annualized return of 3.75%, while APOIX has yielded a comparatively lower 3.02% annualized return.

EIRRX

• 1D: 0.00%
• 1M: -0.49%
• YTD: 0.85%
• 6M: 0.85%
• 1Y: 2.83%
• 3Y*: 4.92%
• 5Y*: 3.52%
• 10Y*: 3.75%

APOIX

• 1D: 0.10%
• 1M: -0.44%
• YTD: 1.28%
• 6M: 1.28%
• 1Y: 3.18%
• 3Y*: 4.66%
• 5Y*: 2.84%
• 10Y*: 3.02%

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

EIRRX vs. APOIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
EIRRX Eaton Vance Short Duration Inflation-Protected Income Fund	0.85%	4.63%	5.65%	6.33%	-3.08%	7.84%	5.25%	5.60%	-0.15%	1.94%
APOIX American Century Short Duration Inflation Protection Bond Fund Investor Class	1.28%	5.95%	4.15%	3.82%	-3.89%	6.30%	5.06%	4.77%	1.81%	0.73%

Correlation

The correlation between EIRRX and APOIX is 0.81, 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	0.81
Correlation (3Y) Calculated over the trailing 3-year period	0.83
Correlation (5Y) Calculated over the trailing 5-year period	0.85
Correlation (10Y) Calculated over the trailing 10-year period	0.77
Correlation (All Time) Calculated using the full available price history since Aug 3, 2012	0.76

The correlation between EIRRX and APOIX has been stable across timeframes, ranging from 0.76 to 0.85 - a consistent structural relationship.

Return for Risk

EIRRX vs. APOIX — Risk / Return Rank

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

EIRRX

EIRRX Risk / Return Rank: 69
EIRRX Sharpe Ratio Rank: 54
EIRRX Sortino Ratio Rank: 61
EIRRX Omega Ratio Rank: 73
EIRRX Calmar Ratio Rank: 82
EIRRX Martin Ratio Rank: 76

APOIX

APOIX Risk / Return Rank: 71
APOIX Sharpe Ratio Rank: 54
APOIX Sortino Ratio Rank: 65
APOIX Omega Ratio Rank: 64
APOIX Calmar Ratio Rank: 90
APOIX Martin Ratio Rank: 83

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.

EIRRX vs. APOIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Eaton Vance Short Duration Inflation-Protected Income Fund (EIRRX) 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.

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.

	EIRRX	APOIX	Difference
Sharpe ratio: Return per unit of total volatility	1.80	1.78	+0.02
Sortino ratio: Return per unit of downside risk	2.68	2.74	-0.06
Omega ratio: Gain probability vs. loss probability	1.40	1.36	+0.04
Calmar ratio: Return relative to maximum drawdown	3.33	4.01	-0.69
Martin ratio: Return relative to average drawdown	12.02	13.00	-0.98

EIRRX vs. APOIX - Sharpe Ratio Comparison

The current EIRRX Sharpe Ratio is 1.80, which is comparable to the APOIX Sharpe Ratio of 1.78. The chart below compares the historical Sharpe Ratios of EIRRX 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.

Drawdowns

EIRRX vs. APOIX - Drawdown Comparison

The maximum EIRRX drawdown since its inception was -10.27%, smaller than the maximum APOIX drawdown of -14.54%. Use the drawdown chart below to compare losses from any high point for EIRRX and APOIX.

Drawdown Indicators

	EIRRX	APOIX	Difference
Max Drawdown Largest peak-to-trough decline	-10.27%	-14.54%	+4.27%
Max Drawdown (1Y) Largest decline over 1 year	-0.89%	-0.82%	-0.07%
Max Drawdown (3Y) Largest decline over 3 years	-1.67%	-1.42%	-0.25%
Max Drawdown (5Y) Largest decline over 5 years	-6.22%	-6.58%	+0.36%
Max Drawdown (10Y) Largest decline over 10 years	-10.27%	-6.58%	-3.69%
Current Drawdown Current decline from peak	-0.88%	-0.73%	-0.15%
Average Drawdown Average peak-to-trough decline	-0.99%	-1.99%	+1.00%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.24%	0.25%	-0.01%

Volatility

EIRRX vs. APOIX - Volatility Comparison

Eaton Vance Short Duration Inflation-Protected Income Fund (EIRRX) and American Century Short Duration Inflation Protection Bond Fund Investor Class (APOIX) have volatilities of 0.70% and 0.67%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	EIRRX	APOIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.70%	0.67%	+0.03%
Volatility (6M) Calculated over the trailing 6-month period	1.31%	1.35%	-0.04%
Volatility (1Y) Calculated over the trailing 1-year period	1.63%	1.85%	-0.22%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.84%	3.31%	-0.47%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.77%	2.85%	-0.08%

EIRRX vs. APOIX - Expense Ratio Comparison

EIRRX has a 0.64% expense ratio, which is higher than APOIX's 0.57% expense ratio.

Dividends

EIRRX vs. APOIX - Dividend Comparison

EIRRX's dividend yield for the trailing twelve months is around 4.10%, more than APOIX's 3.55% 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	3.55%	3.99%	2.31%	2.78%	5.63%	3.92%	0.81%	1.69%	3.99%	1.52%	0.42%	0.00%
EIRRX Eaton Vance Short Duration Inflation-Protected Income Fund	4.10%	3.57%	4.08%	4.50%	5.07%	3.54%	2.21%	2.66%	2.91%	2.13%	2.24%	2.05%

Frequently Asked Questions

Can I hold both EIRRX and APOIX in my portfolio?

EIRRX and APOIX have a correlation of 0.81, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, EIRRX or APOIX?

EIRRX has higher volatility (0.70%) compared to APOIX (0.67%). In terms of maximum drawdown, EIRRX dropped -10.27% vs APOIX's -14.54%.

Which has better risk-adjusted returns?

EIRRX currently has the higher Sharpe Ratio (1.80 vs 1.78), 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.