VBISX vs. VBIRX

Last updated Jun 3, 2026

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

Performance

VBISX vs. VBIRX - Performance Comparison

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

Returns By Period

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

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%

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%

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

VBISX vs. VBIRX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
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%
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%

Correlation

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

Return for Risk

VBISX vs. VBIRX — Risk / Return Rank

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

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

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

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.

VBISX vs. VBIRX - Risk-Adjusted Trends Comparison

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

	VBISX	VBIRX	Difference
Sharpe ratio Return per unit of total volatility	1.59	1.62	-0.03
Sortino ratio Return per unit of downside risk	2.67	2.73	-0.06
Omega ratio Gain probability vs. loss probability	1.32	1.32	0.00
Calmar ratio Return relative to maximum drawdown	2.57	2.64	-0.07
Martin ratio Return relative to average drawdown	8.32	8.63	-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.

VBISX vs. VBIRX - Sharpe Ratio Comparison

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

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

Drawdowns

VBISX vs. VBIRX - Drawdown Comparison

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

Drawdown Indicators

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

Volatility

VBISX vs. VBIRX - Volatility Comparison

Vanguard Short-Term Bond Index Fund (VBISX) and Vanguard Short-Term Bond Index Fund Admiral Shares (VBIRX) have volatilities of 0.69% and 0.71%, 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

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

VBISX vs. VBIRX - Expense Ratio Comparison

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

VBISX vs. VBIRX - Dividend Comparison

VBISX's dividend yield for the trailing twelve months is around 3.90%, less than VBIRX's 3.99% 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 VBISX and VBIRX in my portfolio?

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

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

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.