VMBSX vs. VCOBX
Compare and contrast key facts about Vanguard Mortgage-Backed Securities Index Fund Admiral Shares (VMBSX) and Vanguard Core Bond Fund Admiral Shares (VCOBX).
VMBSX is managed by Vanguard. It was launched on Dec 3, 2009. VCOBX is managed by Vanguard. It was launched on Mar 28, 2016.
Performance
VMBSX vs. VCOBX - Performance Comparison
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VMBSX vs. VCOBX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
VMBSX Vanguard Mortgage-Backed Securities Index Fund Admiral Shares | 0.42% | 8.43% | 1.76% | 4.99% | -11.56% | -1.35% | 3.74% | 11.47% | 0.87% | 2.32% |
VCOBX Vanguard Core Bond Fund Admiral Shares | -0.05% | 7.73% | 2.21% | 6.39% | -13.13% | -1.51% | 10.41% | 9.64% | -0.85% | 3.89% |
Returns By Period
In the year-to-date period, VMBSX achieves a 0.42% return, which is significantly higher than VCOBX's -0.05% return. Over the past 10 years, VMBSX has underperformed VCOBX with an annualized return of 1.88%, while VCOBX has yielded a comparatively higher 2.24% annualized return.
VMBSX
- 1D
- 0.21%
- 1M
- -1.16%
- YTD
- 0.42%
- 6M
- 1.79%
- 1Y
- 5.36%
- 3Y*
- 4.32%
- 5Y*
- 0.48%
- 10Y*
- 1.88%
VCOBX
- 1D
- 0.22%
- 1M
- -1.42%
- YTD
- -0.05%
- 6M
- 0.75%
- 1Y
- 4.24%
- 3Y*
- 4.38%
- 5Y*
- 0.68%
- 10Y*
- 2.24%
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VMBSX vs. VCOBX - Expense Ratio Comparison
VMBSX has a 0.07% expense ratio, which is lower than VCOBX's 0.10% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.
Return for Risk
VMBSX vs. VCOBX — Risk / Return Rank
VMBSX
VCOBX
VMBSX vs. VCOBX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for Vanguard Mortgage-Backed Securities Index Fund Admiral Shares (VMBSX) and Vanguard Core Bond Fund Admiral Shares (VCOBX). 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.
| VMBSX | VCOBX | Difference | |
|---|---|---|---|
Sharpe ratioReturn per unit of total volatility | 1.31 | 1.11 | +0.20 |
Sortino ratioReturn per unit of downside risk | 1.88 | 1.60 | +0.28 |
Omega ratioGain probability vs. loss probability | 1.24 | 1.20 | +0.04 |
Calmar ratioReturn relative to maximum drawdown | 2.26 | 1.77 | +0.49 |
Martin ratioReturn relative to average drawdown | 6.37 | 5.33 | +1.05 |
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month. | |||
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Sharpe Ratios by Period
| VMBSX | VCOBX | Difference | |
|---|---|---|---|
Sharpe Ratio (1Y)Calculated over the trailing 1-year period | 1.31 | 1.11 | +0.20 |
Sharpe Ratio (5Y)Calculated over the trailing 5-year period | 0.08 | 0.12 | -0.04 |
Sharpe Ratio (10Y)Calculated over the trailing 10-year period | 0.39 | 0.47 | -0.08 |
Sharpe Ratio (All Time)Calculated using the full available price history | 0.59 | 0.48 | +0.11 |
Correlation
The correlation between VMBSX and VCOBX is 0.88, which is considered to be high. That indicates a strong positive relationship between their price movements. Having highly-correlated positions in a portfolio may signal a lack of diversification, potentially leading to increased risk during market downturns.
Dividends
VMBSX vs. VCOBX - Dividend Comparison
VMBSX's dividend yield for the trailing twelve months is around 3.86%, less than VCOBX's 4.35% yield.
| TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
VMBSX Vanguard Mortgage-Backed Securities Index Fund Admiral Shares | 3.86% | 4.18% | 4.24% | 3.28% | 2.31% | 0.99% | 2.00% | 7.48% | 2.72% | 2.16% | 1.98% | 2.01% |
VCOBX Vanguard Core Bond Fund Admiral Shares | 4.35% | 4.80% | 5.04% | 4.44% | 3.01% | 1.23% | 3.09% | 3.08% | 3.10% | 2.20% | 2.29% | 0.00% |
Drawdowns
VMBSX vs. VCOBX - Drawdown Comparison
The maximum VMBSX drawdown since its inception was -17.44%, roughly equal to the maximum VCOBX drawdown of -18.14%. Use the drawdown chart below to compare losses from any high point for VMBSX and VCOBX.
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Drawdown Indicators
| VMBSX | VCOBX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -17.44% | -18.14% | +0.70% |
Max Drawdown (1Y)Largest decline over 1 year | -2.59% | -2.70% | +0.11% |
Max Drawdown (5Y)Largest decline over 5 years | -17.12% | -18.03% | +0.91% |
Max Drawdown (10Y)Largest decline over 10 years | -17.44% | -18.14% | +0.70% |
Current DrawdownCurrent decline from peak | -1.60% | -1.88% | +0.28% |
Average DrawdownAverage peak-to-trough decline | -2.49% | -4.22% | +1.73% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.92% | 0.90% | +0.02% |
Volatility
VMBSX vs. VCOBX - Volatility Comparison
Vanguard Mortgage-Backed Securities Index Fund Admiral Shares (VMBSX) and Vanguard Core Bond Fund Admiral Shares (VCOBX) have volatilities of 1.66% and 1.60%, 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.
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Volatility by Period
| VMBSX | VCOBX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.66% | 1.60% | +0.06% |
Volatility (6M)Calculated over the trailing 6-month period | 2.50% | 2.46% | +0.04% |
Volatility (1Y)Calculated over the trailing 1-year period | 4.32% | 4.15% | +0.17% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.36% | 5.75% | +0.61% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 4.83% | 4.74% | +0.09% |