FSTDX vs. FSPWX

Last updated Jun 4, 2026

FSTDX (Fidelity Series 5+ Year Inflation-Protected Bond Index Fund) and FSPWX (Fidelity SAI Inflation-Protected Bond Index Fund) are both Inflation-Protected Bonds funds from Fidelity. Over the past year, FSTDX returned 5.99% vs 5.38% for FSPWX. Their correlation of 0.94 suggests significant overlap in exposure. FSTDX charges 0.00%/yr vs 0.05%/yr for FSPWX.

Performance

FSTDX vs. FSPWX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Series 5+ Year Inflation-Protected Bond Index Fund (FSTDX) and Fidelity SAI Inflation-Protected Bond Index Fund (FSPWX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FSTDX achieves a 1.50% return, which is significantly lower than FSPWX's 1.83% return.

FSTDX

• 1D: 0.00%
• 1M: 0.26%
• YTD: 1.50%
• 6M: 0.69%
• 1Y: 5.99%
• 3Y*: 2.89%
• 5Y*: —
• 10Y*: —

FSPWX

• 1D: 0.00%
• 1M: 0.20%
• YTD: 1.83%
• 6M: 1.35%
• 1Y: 5.38%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

FSTDX vs. FSPWX - Yearly Performance Comparison

	2026 (YTD)	2025	2024
FSTDX Fidelity Series 5+ Year Inflation-Protected Bond Index Fund	1.50%	7.38%	-3.68%
FSPWX Fidelity SAI Inflation-Protected Bond Index Fund	1.83%	6.76%	-1.32%

Correlation

The correlation between FSTDX and FSPWX is 0.93, 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	0.93
Correlation (All Time) Calculated using the full available price history since Aug 23, 2024	0.94

The correlation between FSTDX and FSPWX has been stable across timeframes, ranging from 0.93 to 0.94 - a consistent structural relationship.

Return for Risk

FSTDX vs. FSPWX — Risk / Return Rank

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

FSTDX

FSTDX Risk / Return Rank: 17
FSTDX Sharpe Ratio Rank: 16
FSTDX Sortino Ratio Rank: 16
FSTDX Omega Ratio Rank: 14
FSTDX Calmar Ratio Rank: 20
FSTDX Martin Ratio Rank: 17

FSPWX

FSPWX Risk / Return Rank: 36
FSPWX Sharpe Ratio Rank: 30
FSPWX Sortino Ratio Rank: 33
FSPWX Omega Ratio Rank: 30
FSPWX Calmar Ratio Rank: 49
FSPWX Martin Ratio Rank: 37

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.

FSTDX vs. FSPWX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Series 5+ Year Inflation-Protected Bond Index Fund (FSTDX) and Fidelity SAI Inflation-Protected Bond Index Fund (FSPWX). 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.

	FSTDX	FSPWX	Difference
Sharpe ratio: Return per unit of total volatility	1.11	1.56	-0.45
Sortino ratio: Return per unit of downside risk	1.66	2.39	-0.73
Omega ratio: Gain probability vs. loss probability	1.20	1.29	-0.09
Calmar ratio: Return relative to maximum drawdown	1.63	2.67	-1.04
Martin ratio: Return relative to average drawdown	4.64	8.19	-3.55
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FSTDX vs. FSPWX - Sharpe Ratio Comparison

The current FSTDX Sharpe Ratio is 1.11, which is comparable to the FSPWX Sharpe Ratio of 1.56. The chart below compares the historical Sharpe Ratios of FSTDX and FSPWX, 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

	FSTDX	FSPWX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.11	1.56	-0.45
Sharpe Ratio (All Time) Calculated using the full available price history	-0.18	1.00	-1.18

Drawdowns

FSTDX vs. FSPWX - Drawdown Comparison

The maximum FSTDX drawdown since its inception was -24.29%, which is greater than FSPWX's maximum drawdown of -3.84%. Use the drawdown chart below to compare losses from any high point for FSTDX and FSPWX.

Drawdown Indicators

	FSTDX	FSPWX	Difference
Max Drawdown Largest peak-to-trough decline	-24.29%	-3.84%	-20.45%
Max Drawdown (1Y) Largest decline over 1 year	-3.60%	-1.95%	-1.65%
Max Drawdown (3Y) Largest decline over 3 years	-8.73%	—	—
Current Drawdown Current decline from peak	-10.45%	0.00%	-10.45%
Average Drawdown Average peak-to-trough decline	-14.04%	-0.98%	-13.06%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.26%	0.64%	+0.62%

Volatility

FSTDX vs. FSPWX - Volatility Comparison

Fidelity Series 5+ Year Inflation-Protected Bond Index Fund (FSTDX) has a higher volatility of 1.42% compared to Fidelity SAI Inflation-Protected Bond Index Fund (FSPWX) at 0.92%. This indicates that FSTDX's price experiences larger fluctuations and is considered to be riskier than FSPWX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FSTDX	FSPWX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.42%	0.92%	+0.50%
Volatility (6M) Calculated over the trailing 6-month period	3.63%	2.28%	+1.35%
Volatility (1Y) Calculated over the trailing 1-year period	5.31%	3.35%	+1.96%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	9.46%	4.06%	+5.40%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	9.46%	4.06%	+5.40%

FSTDX vs. FSPWX - Expense Ratio Comparison

FSTDX has a 0.00% expense ratio, which is lower than FSPWX's 0.05% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

FSTDX vs. FSPWX - Dividend Comparison

FSTDX's dividend yield for the trailing twelve months is around 3.98%, more than FSPWX's 3.76% yield.

Position	TTM	2025	2024	2023	2022	2021
FSPWX Fidelity SAI Inflation-Protected Bond Index Fund	3.76%	4.19%	0.69%	0.00%	0.00%	0.00%
FSTDX Fidelity Series 5+ Year Inflation-Protected Bond Index Fund	3.98%	4.38%	3.58%	3.28%	6.69%	0.88%

Frequently Asked Questions

Can I hold both FSTDX and FSPWX in my portfolio?

With a correlation of 0.93, FSTDX and FSPWX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, FSTDX or FSPWX?

FSTDX has higher volatility (1.42%) compared to FSPWX (0.92%). In terms of maximum drawdown, FSTDX dropped -24.29% vs FSPWX's -3.84%.

Which has better risk-adjusted returns?

FSPWX currently has the higher Sharpe Ratio (1.56 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.