VBIRX vs. VBISX

Last updated Jun 3, 2026

VBIRX (Vanguard Short-Term Bond Index Fund Admiral Shares) and VBISX (Vanguard Short-Term Bond Index Fund) are both mutual funds - VBIRX is a Total Bond Market fund managed by Vanguard, while VBISX is a Short-Term Bond fund managed by Vanguard. Over the past 10 years, VBIRX returned 1.92%/yr vs 1.79%/yr for VBISX. With a 0.99 correlation, they move nearly in lockstep. VBIRX charges 0.07%/yr vs 0.15%/yr for VBISX.

Performance

VBIRX vs. VBISX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Short-Term Bond Index Fund Admiral Shares (VBIRX) and Vanguard Short-Term Bond Index Fund (VBISX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VBIRX achieves a 0.30% return, which is significantly higher than VBISX's 0.26% return. Over the past 10 years, VBIRX has outperformed VBISX with an annualized return of 1.92%, while VBISX has yielded a comparatively lower 1.79% annualized return.

VBIRX

• 1D: -0.10%
• 1M: -0.05%
• YTD: 0.30%
• 6M: 0.64%
• 1Y: 3.74%
• 3Y*: 4.42%
• 5Y*: 1.61%
• 10Y*: 1.92%

VBISX

• 1D: -0.10%
• 1M: -0.06%
• YTD: 0.26%
• 6M: 0.59%
• 1Y: 3.64%
• 3Y*: 4.14%
• 5Y*: 1.42%
• 10Y*: 1.79%

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

VBIRX vs. VBISX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VBIRX Vanguard Short-Term Bond Index Fund Admiral Shares	0.30%	6.09%	3.75%	4.87%	-5.63%	-1.20%	4.69%	4.86%	1.37%	1.18%
VBISX Vanguard Short-Term Bond Index Fund	0.26%	5.67%	3.66%	4.54%	-5.61%	-1.35%	4.63%	4.78%	1.27%	1.10%

Correlation

The correlation between VBIRX and VBISX is 0.97 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.97
Correlation (3Y) Calculated over the trailing 3-year period	0.97
Correlation (5Y) Calculated over the trailing 5-year period	0.98
Correlation (10Y) Calculated over the trailing 10-year period	0.98
Correlation (All Time) Calculated using the full available price history since Nov 13, 2001	0.99

The correlation between VBIRX and VBISX has been stable across timeframes, ranging from 0.97 to 0.99 - a consistent structural relationship.

Return for Risk

VBIRX vs. VBISX — Risk / Return Rank

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

VBIRX

VBIRX Risk / Return Rank: 39
VBIRX Sharpe Ratio Rank: 30
VBIRX Sortino Ratio Rank: 43
VBIRX Omega Ratio Rank: 36
VBIRX Calmar Ratio Rank: 47
VBIRX Martin Ratio Rank: 39

VBISX

VBISX Risk / Return Rank: 37
VBISX Sharpe Ratio Rank: 30
VBISX Sortino Ratio Rank: 40
VBISX Omega Ratio Rank: 36
VBISX Calmar Ratio Rank: 45
VBISX 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.

VBIRX vs. VBISX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Short-Term Bond Index Fund Admiral Shares (VBIRX) and Vanguard Short-Term Bond Index Fund (VBISX). 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.

	VBIRX	VBISX	Difference
Sharpe ratio Return per unit of total volatility	1.62	1.59	+0.03
Sortino ratio Return per unit of downside risk	2.73	2.67	+0.06
Omega ratio Gain probability vs. loss probability	1.32	1.32	0.00
Calmar ratio Return relative to maximum drawdown	2.64	2.57	+0.07
Martin ratio Return relative to average drawdown	8.63	8.32	+0.31
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VBIRX vs. VBISX - Sharpe Ratio Comparison

The current VBIRX Sharpe Ratio is 1.62, which is comparable to the VBISX Sharpe Ratio of 1.59. The chart below compares the historical Sharpe Ratios of VBIRX and VBISX, 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

	VBIRX	VBISX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.62	1.59	+0.03
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.55	0.48	+0.06
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.80	0.75	+0.05
Sharpe Ratio (All Time) Calculated using the full available price history	0.97	1.34	-0.37

Drawdowns

VBIRX vs. VBISX - Drawdown Comparison

The maximum VBIRX drawdown since its inception was -8.69%, roughly equal to the maximum VBISX drawdown of -8.79%. Use the drawdown chart below to compare losses from any high point for VBIRX and VBISX.

Drawdown Indicators

	VBIRX	VBISX	Difference
Max Drawdown Largest peak-to-trough decline	-8.69%	-8.79%	+0.10%
Max Drawdown (1Y) Largest decline over 1 year	-1.54%	-1.54%	0.00%
Max Drawdown (3Y) Largest decline over 3 years	-1.55%	-1.55%	0.00%
Max Drawdown (5Y) Largest decline over 5 years	-8.64%	-8.72%	+0.08%
Max Drawdown (10Y) Largest decline over 10 years	-8.69%	-8.79%	+0.10%
Current Drawdown Current decline from peak	-0.63%	-0.66%	+0.03%
Average Drawdown Average peak-to-trough decline	-0.99%	-0.87%	-0.12%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.47%	0.48%	-0.01%

Volatility

VBIRX vs. VBISX - Volatility Comparison

Vanguard Short-Term Bond Index Fund Admiral Shares (VBIRX) and Vanguard Short-Term Bond Index Fund (VBISX) have volatilities of 0.71% and 0.69%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VBIRX	VBISX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.71%	0.69%	+0.02%
Volatility (6M) Calculated over the trailing 6-month period	1.63%	1.62%	+0.01%
Volatility (1Y) Calculated over the trailing 1-year period	2.26%	2.24%	+0.02%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.96%	2.94%	+0.02%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.40%	2.39%	+0.01%

VBIRX vs. VBISX - Expense Ratio Comparison

VBIRX has a 0.07% expense ratio, which is lower than VBISX's 0.15% 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

VBIRX vs. VBISX - Dividend Comparison

VBIRX's dividend yield for the trailing twelve months is around 3.99%, more than VBISX's 3.90% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
VBIRX Vanguard Short-Term Bond Index Fund Admiral Shares	3.99%	3.83%	3.37%	2.41%	1.46%	1.22%	1.77%	2.24%	2.03%	1.66%	1.50%	1.41%
VBISX Vanguard Short-Term Bond Index Fund	3.90%	3.44%	3.29%	2.10%	1.38%	1.16%	1.72%	2.16%	1.92%	1.58%	1.42%	1.34%

Frequently Asked Questions

Can I hold both VBIRX and VBISX in my portfolio?

With a correlation of 0.97, VBIRX and VBISX 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, VBIRX or VBISX?

VBIRX has higher volatility (0.71%) compared to VBISX (0.69%). In terms of maximum drawdown, VBIRX dropped -8.69% vs VBISX's -8.79%.

Which has better risk-adjusted returns?

VBIRX currently has the higher Sharpe Ratio (1.62 vs 1.59), 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.