BILS vs. FZOLX

Last updated Jun 4, 2026

BILS (SPDR Bloomberg 3-12 Month T-Bill ETF) and FZOLX (Fidelity SAI Low Duration Income Fund) are both Ultrashort Bond funds. Over the past 5 years, BILS returned 3.29%/yr vs 3.53%/yr for FZOLX. At a 0.19 correlation, their price movements are largely independent. BILS charges 0.14%/yr vs 0.22%/yr for FZOLX.

Performance

BILS vs. FZOLX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in SPDR Bloomberg 3-12 Month T-Bill ETF (BILS) and Fidelity SAI Low Duration Income Fund (FZOLX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both stocks are quite close, with BILS having a 1.40% return and FZOLX slightly lower at 1.36%.

BILS

• 1D: -0.01%
• 1M: 0.28%
• YTD: 1.40%
• 6M: 1.73%
• 1Y: 3.90%
• 3Y*: 4.66%
• 5Y*: 3.29%
• 10Y*: —

FZOLX

• 1D: 0.00%
• 1M: 0.32%
• YTD: 1.36%
• 6M: 1.79%
• 1Y: 4.26%
• 3Y*: 5.14%
• 5Y*: 3.53%
• 10Y*: —

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

BILS vs. FZOLX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020
BILS SPDR Bloomberg 3-12 Month T-Bill ETF	1.40%	4.23%	5.17%	4.92%	0.90%	-0.08%	0.00%
FZOLX Fidelity SAI Low Duration Income Fund	1.36%	4.85%	5.59%	5.72%	0.34%	-0.04%	0.21%

Correlation

The correlation between BILS and FZOLX is 0.14, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.14
Correlation (3Y) Calculated over the trailing 3-year period	0.16
Correlation (5Y) Calculated over the trailing 5-year period	0.20
Correlation (All Time) Calculated using the full available price history since Sep 25, 2020	0.19

Return for Risk

BILS vs. FZOLX — Risk / Return Rank

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

BILS

BILS Risk / Return Rank: 100
BILS Sharpe Ratio Rank: 100
BILS Sortino Ratio Rank: 100
BILS Omega Ratio Rank: 100
BILS Calmar Ratio Rank: 100
BILS Martin Ratio Rank: 100

FZOLX

FZOLX Risk / Return Rank: 98
FZOLX Sharpe Ratio Rank: 95
FZOLX Sortino Ratio Rank: 99
FZOLX Omega Ratio Rank: 99
FZOLX Calmar Ratio Rank: 99
FZOLX Martin Ratio Rank: 100

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.

BILS vs. FZOLX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for SPDR Bloomberg 3-12 Month T-Bill ETF (BILS) and Fidelity SAI Low Duration Income Fund (FZOLX). 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.

	BILS	FZOLX	Difference
Sharpe ratio: Return per unit of total volatility	16.80	3.36	+13.44
Sortino ratio: Return per unit of downside risk	100.82	10.53	+90.29
Omega ratio: Gain probability vs. loss probability	42.08	3.63	+38.45
Calmar ratio: Return relative to maximum drawdown	129.91	14.30	+115.60
Martin ratio: Return relative to average drawdown	1,442.41	74.84	+1,367.57
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BILS vs. FZOLX - Sharpe Ratio Comparison

The current BILS Sharpe Ratio is 16.80, which is higher than the FZOLX Sharpe Ratio of 3.36. The chart below compares the historical Sharpe Ratios of BILS and FZOLX, 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

	BILS	FZOLX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	16.80	3.36	+13.44
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	10.79	2.91	+7.88
Sharpe Ratio (All Time) Calculated using the full available price history	9.79	2.72	+7.08

Drawdowns

BILS vs. FZOLX - Drawdown Comparison

The maximum BILS drawdown since its inception was -0.41%, smaller than the maximum FZOLX drawdown of -1.10%. Use the drawdown chart below to compare losses from any high point for BILS and FZOLX.

Drawdown Indicators

	BILS	FZOLX	Difference
Max Drawdown Largest peak-to-trough decline	-0.41%	-1.10%	+0.69%
Max Drawdown (1Y) Largest decline over 1 year	-0.03%	-0.30%	+0.27%
Max Drawdown (3Y) Largest decline over 3 years	-0.04%	-0.30%	+0.26%
Max Drawdown (5Y) Largest decline over 5 years	-0.38%	-1.10%	+0.72%
Current Drawdown Current decline from peak	-0.01%	0.00%	-0.01%
Average Drawdown Average peak-to-trough decline	-0.04%	-0.13%	+0.09%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.00%	0.06%	-0.06%

Volatility

BILS vs. FZOLX - Volatility Comparison

The current volatility for SPDR Bloomberg 3-12 Month T-Bill ETF (BILS) is 0.06%, while Fidelity SAI Low Duration Income Fund (FZOLX) has a volatility of 0.38%. This indicates that BILS experiences smaller price fluctuations and is considered to be less risky than FZOLX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BILS	FZOLX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.06%	0.38%	-0.32%
Volatility (6M) Calculated over the trailing 6-month period	0.14%	0.88%	-0.74%
Volatility (1Y) Calculated over the trailing 1-year period	0.23%	1.27%	-1.04%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	0.31%	1.22%	-0.91%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	0.30%	1.15%	-0.85%

BILS vs. FZOLX - Expense Ratio Comparison

BILS has a 0.14% expense ratio, which is lower than FZOLX's 0.22% 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

BILS vs. FZOLX - Dividend Comparison

BILS's dividend yield for the trailing twelve months is around 3.81%, less than FZOLX's 5.09% yield.

Position	TTM	2025	2024	2023	2022	2021	2020
BILS SPDR Bloomberg 3-12 Month T-Bill ETF	3.81%	4.08%	5.01%	4.98%	1.61%	0.00%	0.00%
FZOLX Fidelity SAI Low Duration Income Fund	5.09%	5.26%	5.15%	4.03%	1.14%	0.16%	0.01%

Frequently Asked Questions

Can I hold both BILS and FZOLX in my portfolio?

BILS and FZOLX have a correlation of 0.14, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BILS or FZOLX?

FZOLX has higher volatility (0.38%) compared to BILS (0.06%). In terms of maximum drawdown, BILS dropped -0.41% vs FZOLX's -1.10%.

Which has better risk-adjusted returns?

BILS currently has the higher Sharpe Ratio (16.80 vs 3.36), 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.