AMBFX vs. VBAIX

Last updated Jun 3, 2026

AMBFX (American Funds American Balanced Fund® Class F-2) and VBAIX (Vanguard Balanced Index Fund Institutional Shares) are both Diversified Portfolio funds. Over the past 10 years, AMBFX returned 10.45%/yr vs 10.13%/yr for VBAIX. With a 0.96 correlation, they move nearly in lockstep. AMBFX charges 0.35%/yr vs 0.06%/yr for VBAIX.

Performance

AMBFX vs. VBAIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Funds American Balanced Fund® Class F-2 (AMBFX) and Vanguard Balanced Index Fund Institutional Shares (VBAIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, AMBFX achieves a 9.80% return, which is significantly higher than VBAIX's 7.22% return. Both investments have delivered pretty close results over the past 10 years, with AMBFX having a 10.45% annualized return and VBAIX not far behind at 10.13%.

AMBFX

• 1D: 0.20%
• 1M: 3.59%
• YTD: 9.80%
• 6M: 10.73%
• 1Y: 25.43%
• 3Y*: 17.67%
• 5Y*: 9.84%
• 10Y*: 10.45%

VBAIX

• 1D: 0.13%
• 1M: 3.18%
• YTD: 7.22%
• 6M: 7.45%
• 1Y: 19.68%
• 3Y*: 16.05%
• 5Y*: 8.51%
• 10Y*: 10.13%

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

AMBFX vs. VBAIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
AMBFX American Funds American Balanced Fund® Class F-2	9.80%	18.67%	15.25%	13.81%	-11.93%	16.00%	11.06%	19.45%	-2.69%	14.85%
VBAIX Vanguard Balanced Index Fund Institutional Shares	7.22%	13.60%	17.78%	17.55%	-16.87%	14.20%	16.40%	21.79%	-2.83%	13.86%

Correlation

The correlation between AMBFX and VBAIX is 0.94, 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	0.94
Correlation (3Y) Calculated over the trailing 3-year period	0.95
Correlation (5Y) Calculated over the trailing 5-year period	0.96
Correlation (10Y) Calculated over the trailing 10-year period	0.96
Correlation (All Time) Calculated using the full available price history since Aug 4, 2008	0.97

The correlation between AMBFX and VBAIX has been stable across timeframes, ranging from 0.94 to 0.96 - a consistent structural relationship.

Return for Risk

AMBFX vs. VBAIX — Risk / Return Rank

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

AMBFX

AMBFX Risk / Return Rank: 86
AMBFX Sharpe Ratio Rank: 90
AMBFX Sortino Ratio Rank: 87
AMBFX Omega Ratio Rank: 84
AMBFX Calmar Ratio Rank: 81
AMBFX Martin Ratio Rank: 87

VBAIX

VBAIX Risk / Return Rank: 76
VBAIX Sharpe Ratio Rank: 76
VBAIX Sortino Ratio Rank: 74
VBAIX Omega Ratio Rank: 70
VBAIX Calmar Ratio Rank: 75
VBAIX Martin Ratio Rank: 83

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.

AMBFX vs. VBAIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Funds American Balanced Fund® Class F-2 (AMBFX) and Vanguard Balanced Index Fund Institutional Shares (VBAIX). 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.

	AMBFX	VBAIX	Difference
Sharpe ratio Return per unit of total volatility	2.98	2.52	+0.46
Sortino ratio Return per unit of downside risk	4.17	3.60	+0.57
Omega ratio Gain probability vs. loss probability	1.57	1.47	+0.10
Calmar ratio Return relative to maximum drawdown	3.72	3.42	+0.30
Martin ratio Return relative to average drawdown	16.88	15.65	+1.22
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

AMBFX vs. VBAIX - Sharpe Ratio Comparison

The current AMBFX Sharpe Ratio is 2.98, which is comparable to the VBAIX Sharpe Ratio of 2.52. The chart below compares the historical Sharpe Ratios of AMBFX and VBAIX, 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

	AMBFX	VBAIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.98	2.52	+0.46
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.94	0.77	+0.17
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.98	0.91	+0.08
Sharpe Ratio (All Time) Calculated using the full available price history	0.78	0.66	+0.12

Drawdowns

AMBFX vs. VBAIX - Drawdown Comparison

The maximum AMBFX drawdown since its inception was -35.05%, roughly equal to the maximum VBAIX drawdown of -35.82%. Use the drawdown chart below to compare losses from any high point for AMBFX and VBAIX.

Drawdown Indicators

	AMBFX	VBAIX	Difference
Max Drawdown Largest peak-to-trough decline	-35.05%	-35.82%	+0.77%
Max Drawdown (1Y) Largest decline over 1 year	-7.00%	-5.84%	-1.16%
Max Drawdown (3Y) Largest decline over 3 years	-10.64%	-11.57%	+0.93%
Max Drawdown (5Y) Largest decline over 5 years	-18.65%	-21.52%	+2.87%
Max Drawdown (10Y) Largest decline over 10 years	-22.31%	-22.77%	+0.46%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-3.58%	-4.42%	+0.84%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.54%	1.27%	+0.27%

Volatility

AMBFX vs. VBAIX - Volatility Comparison

American Funds American Balanced Fund® Class F-2 (AMBFX) has a higher volatility of 2.67% compared to Vanguard Balanced Index Fund Institutional Shares (VBAIX) at 2.26%. This indicates that AMBFX's price experiences larger fluctuations and is considered to be riskier than VBAIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	AMBFX	VBAIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.67%	2.26%	+0.41%
Volatility (6M) Calculated over the trailing 6-month period	6.87%	6.12%	+0.75%
Volatility (1Y) Calculated over the trailing 1-year period	8.74%	7.91%	+0.83%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	10.50%	11.10%	-0.60%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	10.67%	11.23%	-0.56%

AMBFX vs. VBAIX - Expense Ratio Comparison

AMBFX has a 0.35% expense ratio, which is higher than VBAIX's 0.06% expense ratio.

Dividends

AMBFX vs. VBAIX - Dividend Comparison

AMBFX's dividend yield for the trailing twelve months is around 7.74%, more than VBAIX's 5.23% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AMBFX American Funds American Balanced Fund® Class F-2	7.74%	8.47%	7.40%	2.20%	2.52%	4.50%	4.56%	4.19%	6.20%	4.85%	4.46%	5.81%
VBAIX Vanguard Balanced Index Fund Institutional Shares	5.23%	6.01%	8.01%	4.36%	2.84%	3.20%	2.65%	2.29%	2.33%	1.96%	2.10%	2.10%

Frequently Asked Questions

Can I hold both AMBFX and VBAIX in my portfolio?

With a correlation of 0.94, AMBFX and VBAIX 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, AMBFX or VBAIX?

AMBFX has higher volatility (2.67%) compared to VBAIX (2.26%). In terms of maximum drawdown, AMBFX dropped -35.05% vs VBAIX's -35.82%.

Which has better risk-adjusted returns?

AMBFX currently has the higher Sharpe Ratio (2.98 vs 2.52), 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.