VBIAX vs. AMBFX

Last updated Jun 24, 2026

VBIAX (Vanguard Balanced Index Fund Admiral Shares) and AMBFX (American Funds American Balanced Fund® Class F-2) are both Diversified Portfolio funds. Over the past 10 years, VBIAX returned 9.89%/yr vs 10.56%/yr for AMBFX. With a 0.97 correlation, they move nearly in lockstep. VBIAX charges 0.07%/yr vs 0.35%/yr for AMBFX.

Performance

VBIAX vs. AMBFX - Performance Comparison

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

Returns By Period

In the year-to-date period, VBIAX achieves a 6.36% return, which is significantly lower than AMBFX's 9.50% return. Over the past 10 years, VBIAX has underperformed AMBFX with an annualized return of 9.89%, while AMBFX has yielded a comparatively higher 10.56% annualized return.

VBIAX

• 1D: -0.31%
• 1M: 0.57%
• YTD: 6.36%
• 6M: 5.74%
• 1Y: 17.06%
• 3Y*: 14.33%
• 5Y*: 7.55%
• 10Y*: 9.89%

AMBFX

• 1D: -0.32%
• 1M: 1.44%
• YTD: 9.50%
• 6M: 9.41%
• 1Y: 22.97%
• 3Y*: 17.35%
• 5Y*: 9.88%
• 10Y*: 10.56%

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

VBIAX vs. AMBFX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VBIAX Vanguard Balanced Index Fund Admiral Shares	6.36%	13.61%	14.58%	17.54%	-16.90%	14.21%	16.40%	21.78%	-2.86%	13.89%
AMBFX American Funds American Balanced Fund® Class F-2	9.50%	18.67%	15.25%	13.81%	-11.93%	16.00%	11.06%	19.45%	-2.69%	14.85%

Correlation

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

Return for Risk

VBIAX vs. AMBFX — Risk / Return Rank

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

VBIAX

VBIAX Risk / Return Rank: 67
VBIAX Sharpe Ratio Rank: 63
VBIAX Sortino Ratio Rank: 63
VBIAX Omega Ratio Rank: 61
VBIAX Calmar Ratio Rank: 70
VBIAX Martin Ratio Rank: 78

AMBFX

AMBFX Risk / Return Rank: 83
AMBFX Sharpe Ratio Rank: 86
AMBFX Sortino Ratio Rank: 83
AMBFX Omega Ratio Rank: 81
AMBFX Calmar Ratio Rank: 79
AMBFX Martin Ratio Rank: 86

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.

VBIAX vs. AMBFX - Risk-Adjusted Trends Comparison

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

	VBIAX	AMBFX	Difference
Sharpe ratio: Return per unit of total volatility	2.14	2.59	-0.44
Sortino ratio: Return per unit of downside risk	3.03	3.60	-0.57
Omega ratio: Gain probability vs. loss probability	1.39	1.49	-0.09
Calmar ratio: Return relative to maximum drawdown	3.08	3.40	-0.33
Martin ratio: Return relative to average drawdown	13.64	15.09	-1.45

VBIAX vs. AMBFX - Sharpe Ratio Comparison

The current VBIAX Sharpe Ratio is 2.14, which is comparable to the AMBFX Sharpe Ratio of 2.59. The chart below compares the historical Sharpe Ratios of VBIAX and AMBFX, 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

VBIAX vs. AMBFX - Drawdown Comparison

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

Drawdown Indicators

	VBIAX	AMBFX	Difference
Max Drawdown Largest peak-to-trough decline	-35.90%	-35.05%	-0.85%
Max Drawdown (1Y) Largest decline over 1 year	-5.83%	-7.00%	+1.17%
Max Drawdown (3Y) Largest decline over 3 years	-11.70%	-10.64%	-1.06%
Max Drawdown (5Y) Largest decline over 5 years	-21.53%	-18.65%	-2.88%
Max Drawdown (10Y) Largest decline over 10 years	-22.78%	-22.31%	-0.47%
Current Drawdown Current decline from peak	-0.93%	-0.51%	-0.42%
Average Drawdown Average peak-to-trough decline	-4.44%	-3.58%	-0.86%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.31%	1.57%	-0.26%

Volatility

VBIAX vs. AMBFX - Volatility Comparison

Vanguard Balanced Index Fund Admiral Shares (VBIAX) and American Funds American Balanced Fund® Class F-2 (AMBFX) have volatilities of 3.24% and 3.39%, 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

	VBIAX	AMBFX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.24%	3.39%	-0.15%
Volatility (6M) Calculated over the trailing 6-month period	6.69%	7.31%	-0.62%
Volatility (1Y) Calculated over the trailing 1-year period	8.38%	9.22%	-0.84%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	11.12%	10.57%	+0.55%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	11.25%	10.72%	+0.53%

VBIAX vs. AMBFX - Expense Ratio Comparison

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

Dividends

VBIAX vs. AMBFX - Dividend Comparison

VBIAX's dividend yield for the trailing twelve months is around 5.26%, less than AMBFX's 7.31% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AMBFX American Funds American Balanced Fund® Class F-2	7.31%	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	5.26%	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 VBIAX and AMBFX in my portfolio?

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

AMBFX has higher volatility (3.39%) compared to VBIAX (3.24%). In terms of maximum drawdown, VBIAX dropped -35.90% vs AMBFX's -35.05%.

Which has better risk-adjusted returns?

AMBFX currently has the higher Sharpe Ratio (2.59 vs 2.14), 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.