FSPWX vs. ANBIX

Last updated Jun 24, 2026

FSPWX (Fidelity SAI Inflation-Protected Bond Index Fund) and ANBIX (AB Bond Inflation Strategy) are both Inflation-Protected Bonds funds. Over the past year, FSPWX returned 3.53% vs 2.83% for ANBIX. A 0.79 correlation means they provide meaningful diversification when combined. FSPWX charges 0.05%/yr vs 0.59%/yr for ANBIX.

Performance

FSPWX vs. ANBIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity SAI Inflation-Protected Bond Index Fund (FSPWX) and AB Bond Inflation Strategy (ANBIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FSPWX achieves a 0.83% return, which is significantly higher than ANBIX's 0.60% return.

FSPWX

• 1D: -0.39%
• 1M: 0.00%
• YTD: 0.83%
• 6M: 0.93%
• 1Y: 3.53%
• 3Y*: —
• 5Y*: —
• 10Y*: —

ANBIX

• 1D: -0.29%
• 1M: -0.43%
• YTD: 0.60%
• 6M: 0.79%
• 1Y: 2.83%
• 3Y*: 4.81%
• 5Y*: 2.18%
• 10Y*: 3.47%

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

FSPWX vs. ANBIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024
FSPWX Fidelity SAI Inflation-Protected Bond Index Fund	0.83%	6.76%	-1.32%
ANBIX AB Bond Inflation Strategy	0.60%	7.52%	-0.23%

Correlation

The correlation between FSPWX and ANBIX is 0.75, 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	0.75
Correlation (All Time) Calculated using the full available price history since Aug 22, 2024	0.79

The correlation between FSPWX and ANBIX has been stable across timeframes, ranging from 0.75 to 0.79 - a consistent structural relationship.

Return for Risk

FSPWX vs. ANBIX — Risk / Return Rank

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

FSPWX

FSPWX Risk / Return Rank: 21
FSPWX Sharpe Ratio Rank: 17
FSPWX Sortino Ratio Rank: 18
FSPWX Omega Ratio Rank: 17
FSPWX Calmar Ratio Rank: 28
FSPWX Martin Ratio Rank: 26

ANBIX

ANBIX Risk / Return Rank: 41
ANBIX Sharpe Ratio Rank: 28
ANBIX Sortino Ratio Rank: 31
ANBIX Omega Ratio Rank: 33
ANBIX Calmar Ratio Rank: 61
ANBIX Martin Ratio Rank: 54

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.

FSPWX vs. ANBIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity SAI Inflation-Protected Bond Index Fund (FSPWX) and AB Bond Inflation Strategy (ANBIX). 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.

	FSPWX	ANBIX	Difference
Sharpe ratio: Return per unit of total volatility	1.10	1.41	-0.31
Sortino ratio: Return per unit of downside risk	1.63	2.13	-0.50
Omega ratio: Gain probability vs. loss probability	1.20	1.28	-0.08
Calmar ratio: Return relative to maximum drawdown	1.88	2.89	-1.01
Martin ratio: Return relative to average drawdown	5.69	10.32	-4.63

FSPWX vs. ANBIX - Sharpe Ratio Comparison

The current FSPWX Sharpe Ratio is 1.10, which is comparable to the ANBIX Sharpe Ratio of 1.41. The chart below compares the historical Sharpe Ratios of FSPWX and ANBIX, 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

FSPWX vs. ANBIX - Drawdown Comparison

The maximum FSPWX drawdown since its inception was -3.84%, smaller than the maximum ANBIX drawdown of -11.56%. Use the drawdown chart below to compare losses from any high point for FSPWX and ANBIX.

Drawdown Indicators

	FSPWX	ANBIX	Difference
Max Drawdown Largest peak-to-trough decline	-3.84%	-11.56%	+7.72%
Max Drawdown (1Y) Largest decline over 1 year	-1.95%	-1.05%	-0.90%
Max Drawdown (3Y) Largest decline over 3 years	—	-2.52%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-10.85%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-11.56%	—
Current Drawdown Current decline from peak	-0.98%	-0.99%	+0.01%
Average Drawdown Average peak-to-trough decline	-0.96%	-2.19%	+1.23%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.64%	0.29%	+0.35%

Volatility

FSPWX vs. ANBIX - Volatility Comparison

Fidelity SAI Inflation-Protected Bond Index Fund (FSPWX) has a higher volatility of 1.22% compared to AB Bond Inflation Strategy (ANBIX) at 0.92%. This indicates that FSPWX's price experiences larger fluctuations and is considered to be riskier than ANBIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FSPWX	ANBIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.22%	0.92%	+0.30%
Volatility (6M) Calculated over the trailing 6-month period	2.43%	1.63%	+0.80%
Volatility (1Y) Calculated over the trailing 1-year period	3.35%	2.17%	+1.18%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.07%	4.49%	-0.42%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.07%	4.01%	+0.06%

FSPWX vs. ANBIX - Expense Ratio Comparison

FSPWX has a 0.05% expense ratio, which is lower than ANBIX's 0.59% expense ratio.

Dividends

FSPWX vs. ANBIX - Dividend Comparison

FSPWX's dividend yield for the trailing twelve months is around 3.79%, less than ANBIX's 4.31% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ANBIX AB Bond Inflation Strategy	4.31%	4.93%	3.86%	4.55%	6.47%	4.70%	2.22%	3.19%	3.39%	2.05%	2.13%	1.61%
FSPWX Fidelity SAI Inflation-Protected Bond Index Fund	3.79%	4.19%	0.69%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both FSPWX and ANBIX in my portfolio?

FSPWX and ANBIX have a correlation of 0.75, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FSPWX or ANBIX?

FSPWX has higher volatility (1.22%) compared to ANBIX (0.92%). In terms of maximum drawdown, FSPWX dropped -3.84% vs ANBIX's -11.56%.

Which has better risk-adjusted returns?

ANBIX currently has the higher Sharpe Ratio (1.41 vs 1.10), 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.