AIBAX vs. VBISX

Last updated Jun 5, 2026

AIBAX (American Funds Intermediate Bond Fund of America) and VBISX (Vanguard Short-Term Bond Index Fund) are both Short-Term Bond funds. Over the past 10 years, AIBAX returned 1.68%/yr vs 1.78%/yr for VBISX. Their correlation of 0.82 suggests significant overlap in exposure. AIBAX charges 0.63%/yr vs 0.15%/yr for VBISX.

Performance

AIBAX vs. VBISX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Funds Intermediate Bond Fund of America (AIBAX) 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, AIBAX achieves a -0.10% return, which is significantly lower than VBISX's 0.16% return. Over the past 10 years, AIBAX has underperformed VBISX with an annualized return of 1.68%, while VBISX has yielded a comparatively higher 1.78% annualized return.

AIBAX

• 1D: -0.16%
• 1M: -0.07%
• YTD: -0.10%
• 6M: 0.30%
• 1Y: 3.41%
• 3Y*: 4.03%
• 5Y*: 0.93%
• 10Y*: 1.68%

VBISX

• 1D: -0.10%
• 1M: 0.04%
• YTD: 0.16%
• 6M: 0.59%
• 1Y: 3.34%
• 3Y*: 4.11%
• 5Y*: 1.40%
• 10Y*: 1.78%

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

AIBAX vs. VBISX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
AIBAX American Funds Intermediate Bond Fund of America	-0.10%	6.83%	2.91%	4.09%	-8.02%	-0.89%	7.36%	4.40%	0.92%	1.06%
VBISX Vanguard Short-Term Bond Index Fund	0.16%	5.67%	3.66%	4.54%	-5.61%	-1.35%	4.63%	4.78%	1.27%	1.10%

Correlation

The correlation between AIBAX and VBISX is 0.90, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.90
Correlation (3Y) Calculated over the trailing 3-year period	0.93
Correlation (5Y) Calculated over the trailing 5-year period	0.93
Correlation (10Y) Calculated over the trailing 10-year period	0.88
Correlation (All Time) Calculated using the full available price history since Mar 1, 1994	0.82

The correlation between AIBAX and VBISX shifts across timeframes, from 0.82 (all time) to 0.93 (3 years), reflecting how their relationship changes across market environments.

Return for Risk

AIBAX vs. VBISX — Risk / Return Rank

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

AIBAX

AIBAX Risk / Return Rank: 23
AIBAX Sharpe Ratio Rank: 21
AIBAX Sortino Ratio Rank: 25
AIBAX Omega Ratio Rank: 22
AIBAX Calmar Ratio Rank: 23
AIBAX Martin Ratio Rank: 21

VBISX

VBISX Risk / Return Rank: 36
VBISX Sharpe Ratio Rank: 31
VBISX Sortino Ratio Rank: 41
VBISX Omega Ratio Rank: 37
VBISX Calmar Ratio Rank: 38
VBISX Martin Ratio Rank: 33

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.

AIBAX vs. VBISX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Funds Intermediate Bond Fund of America (AIBAX) 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.

	AIBAX	VBISX	Difference
Sharpe ratio: Return per unit of total volatility	1.31	1.59	-0.28
Sortino ratio: Return per unit of downside risk	2.08	2.67	-0.59
Omega ratio: Gain probability vs. loss probability	1.25	1.32	-0.07
Calmar ratio: Return relative to maximum drawdown	1.76	2.30	-0.54
Martin ratio: Return relative to average drawdown	5.41	7.37	-1.95
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

AIBAX vs. VBISX - Sharpe Ratio Comparison

The current AIBAX Sharpe Ratio is 1.31, which is comparable to the VBISX Sharpe Ratio of 1.59. The chart below compares the historical Sharpe Ratios of AIBAX 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

	AIBAX	VBISX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.31	1.59	-0.28
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.22	0.48	-0.25
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.51	0.75	-0.24
Sharpe Ratio (All Time) Calculated using the full available price history	1.26	1.34	-0.09

Drawdowns

AIBAX vs. VBISX - Drawdown Comparison

The maximum AIBAX drawdown since its inception was -11.42%, which is greater than VBISX's maximum drawdown of -8.79%. Use the drawdown chart below to compare losses from any high point for AIBAX and VBISX.

Drawdown Indicators

	AIBAX	VBISX	Difference
Max Drawdown Largest peak-to-trough decline	-11.42%	-8.79%	-2.63%
Max Drawdown (1Y) Largest decline over 1 year	-2.18%	-1.54%	-0.64%
Max Drawdown (3Y) Largest decline over 3 years	-2.99%	-1.55%	-1.44%
Max Drawdown (5Y) Largest decline over 5 years	-11.33%	-8.72%	-2.61%
Max Drawdown (10Y) Largest decline over 10 years	-11.42%	-8.79%	-2.63%
Current Drawdown Current decline from peak	-1.23%	-0.75%	-0.48%
Average Drawdown Average peak-to-trough decline	-1.19%	-0.87%	-0.32%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.71%	0.48%	+0.23%

Volatility

AIBAX vs. VBISX - Volatility Comparison

American Funds Intermediate Bond Fund of America (AIBAX) has a higher volatility of 0.97% compared to Vanguard Short-Term Bond Index Fund (VBISX) at 0.67%. This indicates that AIBAX's price experiences larger fluctuations and is considered to be riskier than VBISX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	AIBAX	VBISX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.97%	0.67%	+0.30%
Volatility (6M) Calculated over the trailing 6-month period	2.02%	1.58%	+0.44%
Volatility (1Y) Calculated over the trailing 1-year period	2.93%	2.24%	+0.69%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.19%	2.94%	+1.25%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	3.29%	2.38%	+0.91%

AIBAX vs. VBISX - Expense Ratio Comparison

AIBAX has a 0.63% expense ratio, which is higher than VBISX's 0.15% expense ratio.

Dividends

AIBAX vs. VBISX - Dividend Comparison

AIBAX's dividend yield for the trailing twelve months is around 3.86%, less than VBISX's 3.90% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AIBAX American Funds Intermediate Bond Fund of America	3.86%	3.87%	4.00%	3.01%	1.63%	0.91%	3.25%	2.59%	1.66%	1.21%	1.72%	1.85%
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 AIBAX and VBISX in my portfolio?

With a correlation of 0.90, AIBAX 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, AIBAX or VBISX?

AIBAX has higher volatility (0.97%) compared to VBISX (0.67%). In terms of maximum drawdown, AIBAX dropped -11.42% vs VBISX's -8.79%.

Which has better risk-adjusted returns?

VBISX currently has the higher Sharpe Ratio (1.59 vs 1.31), 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.