SDSI vs. FLDB

Last updated Apr 1, 2026

Compare and contrast key facts about American Century Short Duration Strategic Income ETF (SDSI) and Fidelity Low Duration Bond ETF (FLDB).

SDSI and FLDB are both exchange-traded funds (ETFs), meaning they are traded on stock exchanges and can be bought and sold throughout the day. SDSI is a passively managed fund by American Century that tracks the performance of the Bloomberg U.S. 1-3 Year Government/Credit Bond Index. It was launched on Oct 11, 2022. FLDB is an actively managed fund by Fidelity. It was launched on Feb 22, 2024.

Performance

SDSI vs. FLDB - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century Short Duration Strategic Income ETF (SDSI) and Fidelity Low Duration Bond ETF (FLDB). The values are adjusted to include any dividend payments, if applicable.

SDSI vs. FLDB - Yearly Performance Comparison

	2026 (YTD)	2025	2024
SDSI American Century Short Duration Strategic Income ETF	0.25%	6.54%	5.35%
FLDB Fidelity Low Duration Bond ETF	0.80%	4.93%	4.29%

Returns By Period

In the year-to-date period, SDSI achieves a 0.25% return, which is significantly lower than FLDB's 0.80% return.

SDSI

• 1D: 0.39%
• 1M: -0.66%
• YTD: 0.25%
• 6M: 1.57%
• 1Y: 4.98%
• 3Y*: 5.46%
• 5Y*: —
• 10Y*: —

FLDB

• 1D: 0.06%
• 1M: 0.12%
• YTD: 0.80%
• 6M: 1.91%
• 1Y: 4.65%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

SDSI vs. FLDB - Expense Ratio Comparison

SDSI has a 0.33% expense ratio, which is higher than FLDB's 0.20% expense ratio.

SDSI

American Century Short Duration Strategic Income ETF

FLDB

Fidelity Low Duration Bond ETF

Return for Risk

SDSI vs. FLDB — Risk / Return Rank

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

SDSI

SDSI Risk / Return Rank: 94
SDSI Sharpe Ratio Rank: 91
SDSI Sortino Ratio Rank: 93
SDSI Omega Ratio Rank: 96
SDSI Calmar Ratio Rank: 95
SDSI Martin Ratio Rank: 96

FLDB

FLDB Risk / Return Rank: 99
FLDB Sharpe Ratio Rank: 99
FLDB Sortino Ratio Rank: 99
FLDB Omega Ratio Rank: 99
FLDB Calmar Ratio Rank: 99
FLDB Martin Ratio Rank: 99

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.

SDSI vs. FLDB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century Short Duration Strategic Income ETF (SDSI) and Fidelity Low Duration Bond ETF (FLDB). 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.

	SDSI	FLDB	Difference
Sharpe ratio Return per unit of total volatility	2.03	4.45	-2.42
Sortino ratio Return per unit of downside risk	2.81	7.69	-4.89
Omega ratio Gain probability vs. loss probability	1.49	2.09	-0.60
Calmar ratio Return relative to maximum drawdown	3.91	11.28	-7.37
Martin ratio Return relative to average drawdown	16.48	64.34	-47.86
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

SDSI vs. FLDB - Sharpe Ratio Comparison

The current SDSI Sharpe Ratio is 2.03, which is lower than the FLDB Sharpe Ratio of 4.45. The chart below compares the historical Sharpe Ratios of SDSI and FLDB, offering insights into how both investments have performed under varying market conditions. These values are calculated using daily returns over the previous 12 months.

Sharpe Ratios by Period

	SDSI	FLDB	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.03	4.45	-2.42
Sharpe Ratio (All Time) Calculated using the full available price history	2.56	3.62	-1.05

Correlation

The correlation between SDSI and FLDB is 0.23, which is considered to be low. This implies their price changes are not closely related. A low correlation is generally favorable for portfolio diversification, as it helps to reduce overall risk by spreading it across multiple assets with different performance patterns.

Dividends

SDSI vs. FLDB - Dividend Comparison

SDSI's dividend yield for the trailing twelve months is around 4.94%, more than FLDB's 4.55% yield.

	TTM	2025	2024	2023	2022
SDSI American Century Short Duration Strategic Income ETF	4.94%	4.91%	5.49%	5.37%	0.98%
FLDB Fidelity Low Duration Bond ETF	4.55%	4.72%	3.58%	0.00%	0.00%

Drawdowns

SDSI vs. FLDB - Drawdown Comparison

The maximum SDSI drawdown since its inception was -1.29%, which is greater than FLDB's maximum drawdown of -0.49%. Use the drawdown chart below to compare losses from any high point for SDSI and FLDB.

Drawdown Indicators

	SDSI	FLDB	Difference
Max Drawdown Largest peak-to-trough decline	-1.29%	-0.49%	-0.80%
Max Drawdown (1Y) Largest decline over 1 year	-1.29%	-0.40%	-0.89%
Current Drawdown Current decline from peak	-0.68%	0.00%	-0.68%
Average Drawdown Average peak-to-trough decline	-0.25%	-0.05%	-0.20%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.31%	0.07%	+0.24%

Volatility

SDSI vs. FLDB - Volatility Comparison

American Century Short Duration Strategic Income ETF (SDSI) has a higher volatility of 0.80% compared to Fidelity Low Duration Bond ETF (FLDB) at 0.28%. This indicates that SDSI's price experiences larger fluctuations and is considered to be riskier than FLDB based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	SDSI	FLDB	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.80%	0.28%	+0.52%
Volatility (6M) Calculated over the trailing 6-month period	1.19%	0.68%	+0.51%
Volatility (1Y) Calculated over the trailing 1-year period	2.46%	1.07%	+1.39%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.31%	1.33%	+0.98%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.31%	1.33%	+0.98%