VMBIX vs. VTIAX

Last updated Apr 1, 2026

Compare and contrast key facts about Vanguard Mortgage-Backed Securities Index Fund Institutional Shares (VMBIX) and Vanguard Total International Stock Index Fund Admiral Shares (VTIAX).

VMBIX is managed by Vanguard. It was launched on Oct 31, 2013. VTIAX is managed by Vanguard. It was launched on Nov 29, 2010.

Performance

VMBIX vs. VTIAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Mortgage-Backed Securities Index Fund Institutional Shares (VMBIX) and Vanguard Total International Stock Index Fund Admiral Shares (VTIAX). The values are adjusted to include any dividend payments, if applicable.

VMBIX vs. VTIAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VMBIX Vanguard Mortgage-Backed Securities Index Fund Institutional Shares	0.25%	8.44%	1.78%	4.97%	-11.56%	-1.30%	3.77%	6.19%	0.88%	2.38%
VTIAX Vanguard Total International Stock Index Fund Admiral Shares	-1.02%	32.18%	5.34%	15.28%	-16.02%	8.59%	11.27%	21.52%	-14.46%	27.54%

Returns By Period

In the year-to-date period, VMBIX achieves a 0.25% return, which is significantly higher than VTIAX's -1.02% return. Over the past 10 years, VMBIX has underperformed VTIAX with an annualized return of 1.39%, while VTIAX has yielded a comparatively higher 8.51% annualized return.

VMBIX

• 1D: 0.52%
• 1M: -1.75%
• YTD: 0.25%
• 6M: 1.83%
• 1Y: 5.47%
• 3Y*: 4.28%
• 5Y*: 0.50%
• 10Y*: 1.39%

VTIAX

• 1D: -0.17%
• 1M: -11.11%
• YTD: -1.02%
• 6M: 3.45%
• 1Y: 24.00%
• 3Y*: 14.20%
• 5Y*: 6.87%
• 10Y*: 8.51%

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

VMBIX vs. VTIAX - Expense Ratio Comparison

VMBIX has a 0.05% expense ratio, which is lower than VTIAX's 0.11% 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%.

VTIAX

Vanguard Total International Stock Index Fund Admiral Shares

VMBIX

Vanguard Mortgage-Backed Securities Index Fund Institutional Shares

Return for Risk

VMBIX vs. VTIAX — Risk / Return Rank

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

VMBIX

VMBIX Risk / Return Rank: 75
VMBIX Sharpe Ratio Rank: 74
VMBIX Sortino Ratio Rank: 76
VMBIX Omega Ratio Rank: 63
VMBIX Calmar Ratio Rank: 89
VMBIX Martin Ratio Rank: 73

VTIAX

VTIAX Risk / Return Rank: 80
VTIAX Sharpe Ratio Rank: 81
VTIAX Sortino Ratio Rank: 80
VTIAX Omega Ratio Rank: 78
VTIAX Calmar Ratio Rank: 81
VTIAX Martin Ratio Rank: 78

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.

VMBIX vs. VTIAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Mortgage-Backed Securities Index Fund Institutional Shares (VMBIX) and Vanguard Total International Stock Index Fund Admiral Shares (VTIAX). 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.

	VMBIX	VTIAX	Difference
Sharpe ratio Return per unit of total volatility	1.32	1.50	-0.17
Sortino ratio Return per unit of downside risk	1.90	1.99	-0.09
Omega ratio Gain probability vs. loss probability	1.24	1.30	-0.06
Calmar ratio Return relative to maximum drawdown	2.42	1.92	+0.50
Martin ratio Return relative to average drawdown	6.87	7.64	-0.77
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VMBIX vs. VTIAX - Sharpe Ratio Comparison

The current VMBIX Sharpe Ratio is 1.32, which is comparable to the VTIAX Sharpe Ratio of 1.50. The chart below compares the historical Sharpe Ratios of VMBIX and VTIAX, offering insights into how both investments have performed under varying market conditions. These values are calculated using daily returns over the previous 12 months.

Sharpe Ratios by Period

	VMBIX	VTIAX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.32	1.50	-0.17
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.08	0.47	-0.39
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.29	0.54	-0.25
Sharpe Ratio (All Time) Calculated using the full available price history	0.51	0.38	+0.13

Correlation

The correlation between VMBIX and VTIAX is 0.01, which is considered to be low. This implies their price changes are not closely related. A low correlation is generally favorable for portfolio diversification, as it helps to reduce overall risk by spreading it across multiple assets with different performance patterns.

Dividends

VMBIX vs. VTIAX - Dividend Comparison

VMBIX's dividend yield for the trailing twelve months is around 3.89%, more than VTIAX's 3.03% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
VMBIX Vanguard Mortgage-Backed Securities Index Fund Institutional Shares	3.89%	4.20%	4.27%	3.29%	2.33%	1.01%	2.02%	2.76%	2.74%	2.18%	2.13%	2.04%
VTIAX Vanguard Total International Stock Index Fund Admiral Shares	3.03%	3.15%	3.33%	3.22%	3.04%	3.05%	2.10%	3.04%	3.16%	2.73%	2.93%	2.84%

Drawdowns

VMBIX vs. VTIAX - Drawdown Comparison

The maximum VMBIX drawdown since its inception was -17.44%, smaller than the maximum VTIAX drawdown of -35.83%. Use the drawdown chart below to compare losses from any high point for VMBIX and VTIAX.

Drawdown Indicators

	VMBIX	VTIAX	Difference
Max Drawdown Largest peak-to-trough decline	-17.44%	-35.83%	+18.39%
Max Drawdown (1Y) Largest decline over 1 year	-2.58%	-11.28%	+8.70%
Max Drawdown (5Y) Largest decline over 5 years	-17.11%	-29.56%	+12.45%
Max Drawdown (10Y) Largest decline over 10 years	-17.44%	-35.83%	+18.39%
Current Drawdown Current decline from peak	-1.75%	-11.28%	+9.53%
Average Drawdown Average peak-to-trough decline	-2.52%	-8.15%	+5.63%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.91%	2.84%	-1.93%

Volatility

VMBIX vs. VTIAX - Volatility Comparison

The current volatility for Vanguard Mortgage-Backed Securities Index Fund Institutional Shares (VMBIX) is 1.69%, while Vanguard Total International Stock Index Fund Admiral Shares (VTIAX) has a volatility of 6.80%. This indicates that VMBIX experiences smaller price fluctuations and is considered to be less risky than VTIAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VMBIX	VTIAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.69%	6.80%	-5.11%
Volatility (6M) Calculated over the trailing 6-month period	2.47%	10.50%	-8.03%
Volatility (1Y) Calculated over the trailing 1-year period	4.29%	15.53%	-11.24%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.33%	14.80%	-8.47%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.76%	15.83%	-11.07%