FSMOX vs. WFBIX

Last updated Jun 4, 2026

FSMOX (Fidelity SAI Investment Grade Securitized Fund) and WFBIX (iShares U.S. Aggregate Bond Index Fund) are both Intermediate Core Bond funds. Over the past 3 years, FSMOX returned 4.20%/yr vs 5.33%/yr for WFBIX. Their correlation of 0.95 suggests significant overlap in exposure. FSMOX charges 0.33%/yr vs 0.05%/yr for WFBIX.

Performance

FSMOX vs. WFBIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity SAI Investment Grade Securitized Fund (FSMOX) and iShares U.S. Aggregate Bond Index Fund (WFBIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FSMOX achieves a 0.98% return, which is significantly higher than WFBIX's 0.43% return.

FSMOX

• 1D: 0.00%
• 1M: 0.49%
• YTD: 0.98%
• 6M: 1.11%
• 1Y: 7.15%
• 3Y*: 4.20%
• 5Y*: —
• 10Y*: —

WFBIX

• 1D: 0.00%
• 1M: 0.45%
• YTD: 0.43%
• 6M: 0.32%
• 1Y: 5.35%
• 3Y*: 5.33%
• 5Y*: 0.99%
• 10Y*: 1.96%

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

FSMOX vs. WFBIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023
FSMOX Fidelity SAI Investment Grade Securitized Fund	0.98%	8.52%	1.45%	1.16%
WFBIX iShares U.S. Aggregate Bond Index Fund	0.43%	7.16%	1.43%	6.75%

Correlation

The correlation between FSMOX and WFBIX is 0.94, 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	0.94
Correlation (3Y) Calculated over the trailing 3-year period	0.95
Correlation (All Time) Calculated using the full available price history since May 18, 2023	0.95

The correlation between FSMOX and WFBIX has been stable across timeframes, ranging from 0.94 to 0.95 - a consistent structural relationship.

Return for Risk

FSMOX vs. WFBIX — Risk / Return Rank

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

FSMOX

FSMOX Risk / Return Rank: 40
FSMOX Sharpe Ratio Rank: 38
FSMOX Sortino Ratio Rank: 42
FSMOX Omega Ratio Rank: 37
FSMOX Calmar Ratio Rank: 45
FSMOX Martin Ratio Rank: 38

WFBIX

WFBIX Risk / Return Rank: 22
WFBIX Sharpe Ratio Rank: 22
WFBIX Sortino Ratio Rank: 24
WFBIX Omega Ratio Rank: 22
WFBIX Calmar Ratio Rank: 23
WFBIX Martin Ratio Rank: 20

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.

FSMOX vs. WFBIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity SAI Investment Grade Securitized Fund (FSMOX) and iShares U.S. Aggregate Bond Index Fund (WFBIX). 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.

	FSMOX	WFBIX	Difference
Sharpe ratio: Return per unit of total volatility	1.79	1.36	+0.43
Sortino ratio: Return per unit of downside risk	2.72	2.04	+0.68
Omega ratio: Gain probability vs. loss probability	1.33	1.25	+0.08
Calmar ratio: Return relative to maximum drawdown	2.54	1.78	+0.76
Martin ratio: Return relative to average drawdown	8.25	5.34	+2.91
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FSMOX vs. WFBIX - Sharpe Ratio Comparison

The current FSMOX Sharpe Ratio is 1.79, which is higher than the WFBIX Sharpe Ratio of 1.36. The chart below compares the historical Sharpe Ratios of FSMOX and WFBIX, 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

	FSMOX	WFBIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.79	1.36	+0.43
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	0.16	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.38	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.64	0.94	-0.31

Drawdowns

FSMOX vs. WFBIX - Drawdown Comparison

The maximum FSMOX drawdown since its inception was -8.65%, smaller than the maximum WFBIX drawdown of -18.68%. Use the drawdown chart below to compare losses from any high point for FSMOX and WFBIX.

Drawdown Indicators

	FSMOX	WFBIX	Difference
Max Drawdown Largest peak-to-trough decline	-8.65%	-18.68%	+10.03%
Max Drawdown (1Y) Largest decline over 1 year	-2.84%	-3.02%	+0.18%
Max Drawdown (3Y) Largest decline over 3 years	-8.47%	-6.09%	-2.38%
Max Drawdown (5Y) Largest decline over 5 years	—	-17.84%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-18.68%	—
Current Drawdown Current decline from peak	-1.16%	-1.50%	+0.34%
Average Drawdown Average peak-to-trough decline	-1.76%	-2.26%	+0.50%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.87%	1.00%	-0.13%

Volatility

FSMOX vs. WFBIX - Volatility Comparison

Fidelity SAI Investment Grade Securitized Fund (FSMOX) has a higher volatility of 1.48% compared to iShares U.S. Aggregate Bond Index Fund (WFBIX) at 1.34%. This indicates that FSMOX's price experiences larger fluctuations and is considered to be riskier than WFBIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FSMOX	WFBIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.48%	1.34%	+0.14%
Volatility (6M) Calculated over the trailing 6-month period	2.87%	2.83%	+0.04%
Volatility (1Y) Calculated over the trailing 1-year period	4.04%	3.97%	+0.07%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.21%	6.40%	-0.19%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	6.21%	5.17%	+1.04%

FSMOX vs. WFBIX - Expense Ratio Comparison

FSMOX has a 0.33% expense ratio, which is higher than WFBIX's 0.05% expense ratio.

Dividends

FSMOX vs. WFBIX - Dividend Comparison

FSMOX's dividend yield for the trailing twelve months is around 4.46%, more than WFBIX's 3.91% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FSMOX Fidelity SAI Investment Grade Securitized Fund	4.46%	4.44%	5.07%	1.21%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%
WFBIX iShares U.S. Aggregate Bond Index Fund	3.91%	3.78%	3.68%	6.82%	2.60%	2.04%	2.43%	2.88%	2.71%	2.24%	2.25%	2.20%

Frequently Asked Questions

Can I hold both FSMOX and WFBIX in my portfolio?

With a correlation of 0.94, FSMOX and WFBIX 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, FSMOX or WFBIX?

FSMOX has higher volatility (1.48%) compared to WFBIX (1.34%). In terms of maximum drawdown, FSMOX dropped -8.65% vs WFBIX's -18.68%.

Which has better risk-adjusted returns?

FSMOX currently has the higher Sharpe Ratio (1.79 vs 1.36), 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.