AMBFX vs. VBIAX

Last updated Jun 23, 2026

AMBFX (American Funds American Balanced Fund® Class F-2) and VBIAX (Vanguard Balanced Index Fund Admiral Shares) are both Diversified Portfolio funds. Over the past 10 years, AMBFX returned 10.46%/yr vs 9.80%/yr for VBIAX. With a 0.97 correlation, they move nearly in lockstep. AMBFX charges 0.35%/yr vs 0.07%/yr for VBIAX.

Performance

AMBFX vs. VBIAX - 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 Admiral Shares (VBIAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, AMBFX achieves a 9.85% return, which is significantly higher than VBIAX's 6.69% return. Over the past 10 years, AMBFX has outperformed VBIAX with an annualized return of 10.46%, while VBIAX has yielded a comparatively lower 9.80% annualized return.

AMBFX

• 1D: 0.84%
• 1M: 1.76%
• YTD: 9.85%
• 6M: 10.15%
• 1Y: 24.09%
• 3Y*: 17.10%
• 5Y*: 10.15%
• 10Y*: 10.46%

VBIAX

• 1D: 0.79%
• 1M: 0.89%
• YTD: 6.69%
• 6M: 6.29%
• 1Y: 18.22%
• 3Y*: 14.11%
• 5Y*: 7.84%
• 10Y*: 9.80%

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

AMBFX vs. VBIAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
AMBFX American Funds American Balanced Fund® Class F-2	9.85%	18.67%	15.25%	13.81%	-11.93%	16.00%	11.06%	19.45%	-2.69%	14.85%
VBIAX Vanguard Balanced Index Fund Admiral Shares	6.69%	13.61%	14.58%	17.54%	-16.90%	14.21%	16.40%	21.78%	-2.86%	13.89%

Correlation

The correlation between AMBFX and VBIAX 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 1, 2008	0.97

The correlation between AMBFX and VBIAX has been stable across timeframes, ranging from 0.94 to 0.97 - a consistent structural relationship.

Return for Risk

AMBFX vs. VBIAX — Risk / Return Rank

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

AMBFX

AMBFX Risk / Return Rank: 83
AMBFX Sharpe Ratio Rank: 87
AMBFX Sortino Ratio Rank: 83
AMBFX Omega Ratio Rank: 82
AMBFX Calmar Ratio Rank: 79
AMBFX Martin Ratio Rank: 87

VBIAX

VBIAX Risk / Return Rank: 69
VBIAX Sharpe Ratio Rank: 65
VBIAX Sortino Ratio Rank: 65
VBIAX Omega Ratio Rank: 63
VBIAX Calmar Ratio Rank: 71
VBIAX Martin Ratio Rank: 80

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. VBIAX - 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 Admiral Shares (VBIAX). 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.

	AMBFX	VBIAX	Difference
Sharpe ratio: Return per unit of total volatility	2.61	2.18	+0.44
Sortino ratio: Return per unit of downside risk	3.63	3.07	+0.56
Omega ratio: Gain probability vs. loss probability	1.49	1.40	+0.09
Calmar ratio: Return relative to maximum drawdown	3.43	3.12	+0.31
Martin ratio: Return relative to average drawdown	15.23	13.84	+1.39

AMBFX vs. VBIAX - Sharpe Ratio Comparison

The current AMBFX Sharpe Ratio is 2.61, which is comparable to the VBIAX Sharpe Ratio of 2.18. The chart below compares the historical Sharpe Ratios of AMBFX and VBIAX, 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

AMBFX vs. VBIAX - Drawdown Comparison

The maximum AMBFX drawdown since its inception was -35.05%, roughly equal to the maximum VBIAX drawdown of -35.90%. Use the drawdown chart below to compare losses from any high point for AMBFX and VBIAX.

Drawdown Indicators

	AMBFX	VBIAX	Difference
Max Drawdown Largest peak-to-trough decline	-35.05%	-35.90%	+0.85%
Max Drawdown (1Y) Largest decline over 1 year	-7.00%	-5.83%	-1.17%
Max Drawdown (3Y) Largest decline over 3 years	-10.64%	-11.70%	+1.06%
Max Drawdown (5Y) Largest decline over 5 years	-18.65%	-21.53%	+2.88%
Max Drawdown (10Y) Largest decline over 10 years	-22.31%	-22.78%	+0.47%
Current Drawdown Current decline from peak	-0.19%	-0.62%	+0.43%
Average Drawdown Average peak-to-trough decline	-3.58%	-4.44%	+0.86%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.57%	1.31%	+0.26%

Volatility

AMBFX vs. VBIAX - Volatility Comparison

American Funds American Balanced Fund® Class F-2 (AMBFX) and Vanguard Balanced Index Fund Admiral Shares (VBIAX) have volatilities of 3.43% and 3.33%, 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

	AMBFX	VBIAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.43%	3.33%	+0.10%
Volatility (6M) Calculated over the trailing 6-month period	7.35%	6.72%	+0.63%
Volatility (1Y) Calculated over the trailing 1-year period	9.20%	8.36%	+0.84%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	10.57%	11.12%	-0.55%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	10.71%	11.25%	-0.54%

AMBFX vs. VBIAX - Expense Ratio Comparison

AMBFX has a 0.35% expense ratio, which is higher than VBIAX's 0.07% expense ratio.

Dividends

AMBFX vs. VBIAX - Dividend Comparison

AMBFX's dividend yield for the trailing twelve months is around 7.29%, more than VBIAX's 5.25% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AMBFX American Funds American Balanced Fund® Class F-2	7.29%	8.47%	7.40%	2.20%	2.52%	4.50%	4.56%	4.19%	6.20%	4.85%	4.46%	5.81%
VBIAX Vanguard Balanced Index Fund Admiral Shares	5.25%	6.00%	5.27%	4.35%	2.83%	3.19%	2.65%	2.28%	2.32%	1.95%	2.09%	2.09%

Frequently Asked Questions

Can I hold both AMBFX and VBIAX in my portfolio?

With a correlation of 0.94, AMBFX and VBIAX 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 VBIAX?

AMBFX has higher volatility (3.43%) compared to VBIAX (3.33%). In terms of maximum drawdown, AMBFX dropped -35.05% vs VBIAX's -35.90%.

Which has better risk-adjusted returns?

AMBFX currently has the higher Sharpe Ratio (2.61 vs 2.17), 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.