VCOBX vs. VBIAX

Last updated Jun 4, 2026

VCOBX (Vanguard Core Bond Fund Admiral Shares) and VBIAX (Vanguard Balanced Index Fund Admiral Shares) are both mutual funds - VCOBX is a Total Bond Market fund managed by Vanguard, while VBIAX is a Diversified Portfolio fund managed by Vanguard. Over the past 10 years, VCOBX returned 2.19%/yr vs 9.83%/yr for VBIAX. At a 0.16 correlation, their price movements are largely independent. VCOBX charges 0.10%/yr vs 0.07%/yr for VBIAX.

Performance

VCOBX vs. VBIAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Core Bond Fund Admiral Shares (VCOBX) 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, VCOBX achieves a 0.60% return, which is significantly lower than VBIAX's 7.35% return. Over the past 10 years, VCOBX has underperformed VBIAX with an annualized return of 2.19%, while VBIAX has yielded a comparatively higher 9.83% annualized return.

VCOBX

• 1D: 0.00%
• 1M: 0.56%
• YTD: 0.60%
• 6M: 0.47%
• 1Y: 5.73%
• 3Y*: 4.90%
• 5Y*: 0.65%
• 10Y*: 2.19%

VBIAX

• 1D: 0.15%
• 1M: 3.71%
• YTD: 7.35%
• 6M: 7.26%
• 1Y: 19.35%
• 3Y*: 15.04%
• 5Y*: 8.01%
• 10Y*: 9.83%

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

VCOBX vs. VBIAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VCOBX Vanguard Core Bond Fund Admiral Shares	0.60%	7.73%	2.21%	6.39%	-13.13%	-1.51%	10.41%	9.64%	-0.85%	3.89%
VBIAX Vanguard Balanced Index Fund Admiral Shares	7.35%	13.61%	14.58%	17.54%	-16.90%	14.21%	16.40%	21.78%	-2.86%	13.89%

Correlation

The correlation between VCOBX and VBIAX is 0.45, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.45
Correlation (3Y) Calculated over the trailing 3-year period	0.42
Correlation (5Y) Calculated over the trailing 5-year period	0.34
Correlation (10Y) Calculated over the trailing 10-year period	0.17
Correlation (All Time) Calculated using the full available price history since Mar 31, 2016	0.16

Over the past year, VCOBX and VBIAX have become more correlated (0.45) than their long-term average of 0.16, meaning their price movements have been converging.

VCOBX vs. VBIAX - Sectors Allocation Comparison

Sectors	VCOBX	VBIAX
Financial Services	1.0%	12.0%
Technology	0.1%	33.5%
Energy	0.0%	3.7%
Real Estate	0.0%	2.4%
Basic Materials	-	2.0%
Communication Services	-	10.3%
Consumer Cyclical	-	10.0%
Consumer Defensive	-	4.7%
Healthcare	-	9.2%
Industrials	-	9.8%
Utilities	-	2.3%

Return for Risk

VCOBX vs. VBIAX — Risk / Return Rank

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

VCOBX

VCOBX Risk / Return Rank: 31
VCOBX Sharpe Ratio Rank: 30
VCOBX Sortino Ratio Rank: 32
VCOBX Omega Ratio Rank: 30
VCOBX Calmar Ratio Rank: 34
VCOBX Martin Ratio Rank: 27

VBIAX

VBIAX Risk / Return Rank: 76
VBIAX Sharpe Ratio Rank: 76
VBIAX Sortino Ratio Rank: 74
VBIAX Omega Ratio Rank: 70
VBIAX Calmar Ratio Rank: 75
VBIAX 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.

VCOBX vs. VBIAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Core Bond Fund Admiral Shares (VCOBX) 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.

	VCOBX	VBIAX	Difference
Sharpe ratio Return per unit of total volatility	1.57	2.52	-0.95
Sortino ratio Return per unit of downside risk	2.34	3.59	-1.26
Omega ratio Gain probability vs. loss probability	1.29	1.47	-0.18
Calmar ratio Return relative to maximum drawdown	2.20	3.42	-1.22
Martin ratio Return relative to average drawdown	6.56	15.60	-9.04
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VCOBX vs. VBIAX - Sharpe Ratio Comparison

The current VCOBX Sharpe Ratio is 1.57, which is lower than the VBIAX Sharpe Ratio of 2.52. The chart below compares the historical Sharpe Ratios of VCOBX 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.

Sharpe Ratios by Period

	VCOBX	VBIAX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.57	2.52	-0.95
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.11	0.73	-0.61
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.46	0.88	-0.42
Sharpe Ratio (All Time) Calculated using the full available price history	0.48	0.64	-0.15

Drawdowns

VCOBX vs. VBIAX - Drawdown Comparison

The maximum VCOBX drawdown since its inception was -18.14%, smaller than the maximum VBIAX drawdown of -35.90%. Use the drawdown chart below to compare losses from any high point for VCOBX and VBIAX.

Drawdown Indicators

	VCOBX	VBIAX	Difference
Max Drawdown Largest peak-to-trough decline	-18.14%	-35.90%	+17.76%
Max Drawdown (1Y) Largest decline over 1 year	-2.62%	-5.83%	+3.21%
Max Drawdown (3Y) Largest decline over 3 years	-5.63%	-11.70%	+6.07%
Max Drawdown (5Y) Largest decline over 5 years	-18.03%	-21.53%	+3.50%
Max Drawdown (10Y) Largest decline over 10 years	-18.14%	-22.78%	+4.64%
Current Drawdown Current decline from peak	-1.25%	0.00%	-1.25%
Average Drawdown Average peak-to-trough decline	-4.18%	-4.44%	+0.26%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.88%	1.27%	-0.39%

Volatility

VCOBX vs. VBIAX - Volatility Comparison

The current volatility for Vanguard Core Bond Fund Admiral Shares (VCOBX) is 1.33%, while Vanguard Balanced Index Fund Admiral Shares (VBIAX) has a volatility of 2.26%. This indicates that VCOBX experiences smaller price fluctuations and is considered to be less risky than VBIAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VCOBX	VBIAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.33%	2.26%	-0.93%
Volatility (6M) Calculated over the trailing 6-month period	2.66%	6.11%	-3.45%
Volatility (1Y) Calculated over the trailing 1-year period	3.68%	7.90%	-4.22%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.78%	11.05%	-5.27%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.76%	11.21%	-6.45%

VCOBX vs. VBIAX - Expense Ratio Comparison

VCOBX has a 0.10% expense ratio, which is higher than VBIAX'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

VCOBX vs. VBIAX - Dividend Comparison

VCOBX's dividend yield for the trailing twelve months is around 4.73%, less than VBIAX's 5.21% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
VBIAX Vanguard Balanced Index Fund Admiral Shares	5.21%	6.00%	5.27%	4.35%	2.83%	3.19%	2.65%	2.28%	2.32%	1.95%	2.09%	2.09%
VCOBX Vanguard Core Bond Fund Admiral Shares	4.73%	4.80%	5.04%	4.44%	3.01%	1.23%	3.09%	3.08%	3.10%	2.20%	2.29%	0.00%

Frequently Asked Questions

Can I hold both VCOBX and VBIAX in my portfolio?

VCOBX and VBIAX have a correlation of 0.45, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VCOBX or VBIAX?

VBIAX has higher volatility (2.26%) compared to VCOBX (1.33%). In terms of maximum drawdown, VCOBX dropped -18.14% vs VBIAX's -35.90%.

Which has better risk-adjusted returns?

VBIAX currently has the higher Sharpe Ratio (2.52 vs 1.57), 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.