FSTZX vs. APOIX

Last updated Jul 14, 2026

FSTZX (Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund) and APOIX (American Century Short Duration Inflation Protection Bond Fund Investor Class) are both Inflation-Protected Bonds funds. Over the past 3 years, FSTZX returned 4.89%/yr vs 5.04%/yr for APOIX. Their correlation of 0.90 suggests significant overlap in exposure. FSTZX charges 0.00%/yr vs 0.57%/yr for APOIX.

Performance

FSTZX vs. APOIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund (FSTZX) 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, FSTZX achieves a 0.57% return, which is significantly lower than APOIX's 1.67% return.

FSTZX

• 1D: -1.30%
• 1M: -1.20%
• 6M: 0.36%
• YTD: 0.57%
• 1Y: 2.37%
• 3Y*: 4.89%
• 5Y*: —
• 10Y*: —

APOIX

• 1D: 0.00%
• 1M: -0.10%
• 6M: 1.47%
• YTD: 1.67%
• 1Y: 3.19%
• 3Y*: 5.04%
• 5Y*: 2.85%
• 10Y*: 3.01%

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

FSTZX vs. APOIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021
FSTZX Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund	0.57%	5.99%	4.87%	4.67%	-2.83%	1.32%
APOIX American Century Short Duration Inflation Protection Bond Fund Investor Class	1.67%	5.95%	4.15%	3.82%	-3.89%	1.67%

Correlation

The correlation between FSTZX 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	0.87
Correlation (All Time) Calculated using the full available price history since Aug 16, 2021	0.90

The correlation between FSTZX and APOIX has been stable across timeframes, ranging from 0.81 to 0.90 - a consistent structural relationship.

Return for Risk

FSTZX vs. APOIX — Risk / Return Rank

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

FSTZX

FSTZX Risk / Return Rank: 37
FSTZX Sharpe Ratio Rank: 27
FSTZX Sortino Ratio Rank: 20
FSTZX Omega Ratio Rank: 41
FSTZX Calmar Ratio Rank: 30
FSTZX Martin Ratio Rank: 66

APOIX

APOIX Risk / Return Rank: 79
APOIX Sharpe Ratio Rank: 66
APOIX Sortino Ratio Rank: 74
APOIX Omega Ratio Rank: 75
APOIX Calmar Ratio Rank: 93
APOIX Martin Ratio Rank: 85

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.

FSTZX vs. APOIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund (FSTZX) 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.

	FSTZX	APOIX	Difference
Sharpe ratio: Return per unit of total volatility	1.11	1.80	-0.69
Sortino ratio: Return per unit of downside risk	1.40	2.76	-1.36
Omega ratio: Gain probability vs. loss probability	1.26	1.37	-0.10
Calmar ratio: Return relative to maximum drawdown	1.60	4.01	-2.41
Martin ratio: Return relative to average drawdown	9.87	12.18	-2.30

FSTZX vs. APOIX - Sharpe Ratio Comparison

The current FSTZX Sharpe Ratio is 1.11, which is lower than the APOIX Sharpe Ratio of 1.80. The chart below compares the historical Sharpe Ratios of FSTZX 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

FSTZX vs. APOIX - Drawdown Comparison

The maximum FSTZX drawdown since its inception was -5.30%, smaller than the maximum APOIX drawdown of -14.54%. Use the drawdown chart below to compare losses from any high point for FSTZX and APOIX.

Drawdown Indicators

	FSTZX	APOIX	Difference
Max Drawdown Largest peak-to-trough decline	-5.30%	-14.54%	+9.24%
Max Drawdown (1Y) Largest decline over 1 year	-1.49%	-0.82%	-0.67%
Max Drawdown (3Y) Largest decline over 3 years	-1.49%	-1.42%	-0.07%
Max Drawdown (5Y) Largest decline over 5 years	—	-6.58%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-6.58%	—
Current Drawdown Current decline from peak	-1.49%	-0.35%	-1.14%
Average Drawdown Average peak-to-trough decline	-1.08%	-1.98%	+0.90%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.24%	0.27%	-0.03%

Volatility

FSTZX vs. APOIX - Volatility Comparison

Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund (FSTZX) has a higher volatility of 1.50% compared to American Century Short Duration Inflation Protection Bond Fund Investor Class (APOIX) at 0.63%. This indicates that FSTZX'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

	FSTZX	APOIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.50%	0.63%	+0.87%
Volatility (6M) Calculated over the trailing 6-month period	1.84%	1.35%	+0.49%
Volatility (1Y) Calculated over the trailing 1-year period	2.16%	1.83%	+0.33%
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	2.84%	2.85%	-0.01%

FSTZX vs. APOIX - Expense Ratio Comparison

FSTZX has a 0.00% expense ratio, which is lower than APOIX's 0.57% expense ratio.

Dividends

FSTZX vs. APOIX - Dividend Comparison

FSTZX's dividend yield for the trailing twelve months is around 2.87%, less than APOIX's 3.53% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016
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%
FSTZX Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund	2.87%	4.02%	2.78%	2.54%	5.25%	0.82%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both FSTZX and APOIX in my portfolio?

FSTZX 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, FSTZX or APOIX?

FSTZX has higher volatility (1.50%) compared to APOIX (0.63%). In terms of maximum drawdown, FSTZX dropped -5.30% vs APOIX's -14.54%.

Which has better risk-adjusted returns?

APOIX currently has the higher Sharpe Ratio (1.80 vs 1.11), 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.