VFISX vs. FBLTX

Last updated Aug 2, 2026

VFISX (Vanguard Short-Term Treasury Fund Investor Shares) and FBLTX (Fidelity SAI Long-Term Treasury Bond Index Fund) are both Government Bonds funds. Over the past 10 years, VFISX returned 1.57%/yr vs -2.52%/yr for FBLTX. Their 0.58 correlation means they have sometimes moved together and sometimes differently. VFISX charges 0.20%/yr vs 0.03%/yr for FBLTX.

Performance

VFISX vs. FBLTX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Short-Term Treasury Fund Investor Shares (VFISX) and Fidelity SAI Long-Term Treasury Bond Index Fund (FBLTX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VFISX achieves a 0.41% return, which is significantly higher than FBLTX's -3.37% return. Over the past 10 years, VFISX has outperformed FBLTX with an annualized return of 1.57%, while FBLTX has yielded a comparatively lower -2.52% annualized return.

VFISX

• 1D: 0.10%
• 1M: -0.20%
• 6M: 0.20%
• YTD: 0.41%
• 1Y: 2.19%
• 3Y*: 4.07%
• 5Y*: 1.45%
• 10Y*: 1.57%
• ALL TIME*: 3.41%

FBLTX

• 1D: -0.16%
• 1M: -3.63%
• 6M: -3.28%
• YTD: -3.37%
• 1Y: -2.17%
• 3Y*: -2.29%
• 5Y*: -8.31%
• 10Y*: -2.52%
• ALL TIME*: -1.05%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
FBLTX Fidelity SAI Long-Term Treasury Bond Index Fund	$0.00	$0.00	$0.00
VFISX Vanguard Short-Term Treasury Fund Investor Shares	$0.00	$0.00	$0.00

VFISX vs. FBLTX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VFISX Vanguard Short-Term Treasury Fund Investor Shares	0.41%	5.36%	3.75%	3.54%	-4.71%	-0.88%	3.95%	3.60%	1.36%	0.38%
FBLTX Fidelity SAI Long-Term Treasury Bond Index Fund	-3.37%	4.39%	-8.05%	2.71%	-31.84%	-4.89%	18.27%	14.36%	-1.24%	9.06%

Correlation

The correlation between VFISX and FBLTX is 0.59, which is moderate. They have sometimes moved together and sometimes differently, sharing some price drivers without tracking each other closely.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.59
Correlation (3Y) Balances recent behavior with more history.	0.61
Correlation (5Y) Shows whether the relationship held over a longer period.	0.61
Correlation (10Y) Provides a long-term view across more market conditions.	0.57
Correlation (All Time) Calculated using the full available price history since Oct 16, 2015	0.58

The correlation between VFISX and FBLTX has been stable across timeframes, ranging from 0.57 to 0.61 - a consistent structural relationship.

Return for Risk

VFISX vs. FBLTX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

VFISX

VFISX Risk / Return Rank: 65
VFISX Sharpe Ratio Rank: 64
VFISX Sortino Ratio Rank: 76
VFISX Omega Ratio Rank: 73
VFISX Calmar Ratio Rank: 68
VFISX Martin Ratio Rank: 46

FBLTX

FBLTX Risk / Return Rank: 4
FBLTX Sharpe Ratio Rank: 4
FBLTX Sortino Ratio Rank: 4
FBLTX Omega Ratio Rank: 4
FBLTX Calmar Ratio Rank: 4
FBLTX Martin Ratio Rank: 4

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

VFISX vs. FBLTX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Short-Term Treasury Fund Investor Shares (VFISX) and Fidelity SAI Long-Term Treasury Bond Index Fund (FBLTX). 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.

	VFISX	FBLTX	Difference
Sharpe ratio: Return per unit of total volatility	1.50	-0.04	+1.54
Sortino ratio: Return per unit of downside risk	2.53	0.01	+2.52
Omega ratio: Gain probability vs. loss probability	1.31	1.00	+0.31
Calmar ratio: Return relative to maximum drawdown	2.18	-0.05	+2.23
Martin ratio: Return relative to average drawdown	6.39	-0.10	+6.49

VFISX vs. FBLTX - Sharpe Ratio Comparison

The current VFISX Sharpe Ratio is 1.50, which is higher than the FBLTX Sharpe Ratio of -0.04. The chart below compares the historical Sharpe Ratios of VFISX and FBLTX, 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

VFISX vs. FBLTX - Drawdown Comparison

The maximum VFISX drawdown since its inception was -6.86%, smaller than the maximum FBLTX drawdown of -49.06%. Use the drawdown chart below to compare losses from any high point for VFISX and FBLTX.

Drawdown Indicators

	VFISX	FBLTX	Difference
Max Drawdown Largest peak-to-trough decline	-6.86%	-49.06%	+42.20%
Max Drawdown (1Y) Largest decline over 1 year	-1.40%	-7.66%	+6.26%
Max Drawdown (3Y) Largest decline over 3 years	-1.40%	-14.75%	+13.35%
Max Drawdown (5Y) Largest decline over 5 years	-6.75%	-44.19%	+37.44%
Max Drawdown (10Y) Largest decline over 10 years	-6.86%	-49.06%	+42.20%
Current Drawdown Current decline from peak	-0.58%	-42.95%	+42.37%
Average Drawdown Average peak-to-trough decline	-0.65%	-21.28%	+20.63%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.48%	3.54%	-3.06%

Volatility

VFISX vs. FBLTX - Volatility Comparison

The current volatility for Vanguard Short-Term Treasury Fund Investor Shares (VFISX) is 0.47%, while Fidelity SAI Long-Term Treasury Bond Index Fund (FBLTX) has a volatility of 2.48%. This indicates that VFISX experiences smaller price fluctuations and is considered to be less risky than FBLTX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VFISX	FBLTX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.47%	2.48%	-2.01%
Volatility (6M) Calculated over the trailing 6-month period	1.58%	6.79%	-5.21%
Volatility (1Y) Calculated over the trailing 1-year period	2.05%	9.26%	-7.21%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.68%	15.57%	-12.89%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.12%	14.51%	-12.39%

VFISX vs. FBLTX - Expense Ratio Comparison

VFISX has a 0.20% expense ratio, which is higher than FBLTX's 0.03% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

VFISX vs. FBLTX - Dividend Comparison

VFISX's dividend yield for the trailing twelve months is around 3.41%, less than FBLTX's 3.97% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FBLTX Fidelity SAI Long-Term Treasury Bond Index Fund	3.97%	4.04%	3.60%	3.29%	2.25%	1.81%	6.73%	2.39%	2.87%	2.68%	3.70%	0.39%
VFISX Vanguard Short-Term Treasury Fund Investor Shares	3.41%	3.89%	4.38%	3.95%	1.93%	0.52%	2.20%	2.39%	2.10%	1.15%	1.18%	0.83%

Frequently Asked Questions

Can I hold both VFISX and FBLTX in my portfolio?

VFISX and FBLTX have a correlation of 0.59, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VFISX or FBLTX?

FBLTX has higher volatility (2.48%) compared to VFISX (0.47%). In terms of maximum drawdown, VFISX dropped -6.86% vs FBLTX's -49.06%.

Which has better risk-adjusted returns?

VFISX currently has the higher Sharpe Ratio (1.50 vs -0.04), 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.