VMBS vs. GNMA

Last updated Apr 1, 2026

Compare and contrast key facts about Vanguard Mortgage-Backed Securities ETF (VMBS) and iShares GNMA Bond ETF (GNMA).

VMBS and GNMA are both exchange-traded funds (ETFs), meaning they are traded on stock exchanges and can be bought and sold throughout the day. VMBS is a passively managed fund by Vanguard that tracks the performance of the Barclays Capital U.S. MBS Index. It was launched on Nov 19, 2009. GNMA is a passively managed fund by iShares that tracks the performance of the Barclays Capital GNMA Index. It was launched on Feb 14, 2012. Both VMBS and GNMA are passive ETFs, meaning that they are not actively managed but aim to replicate the performance of the underlying index as closely as possible.

Performance

VMBS vs. GNMA - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Mortgage-Backed Securities ETF (VMBS) and iShares GNMA Bond ETF (GNMA). The values are adjusted to include any dividend payments, if applicable.

VMBS vs. GNMA - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VMBS Vanguard Mortgage-Backed Securities ETF	0.41%	8.36%	1.70%	5.34%	-11.90%	-1.28%	3.76%	6.19%	0.91%	2.47%
GNMA iShares GNMA Bond ETF	0.22%	8.25%	1.07%	5.34%	-10.83%	-1.86%	3.51%	5.85%	0.85%	1.74%

Returns By Period

In the year-to-date period, VMBS achieves a 0.41% return, which is significantly higher than GNMA's 0.22% return. Over the past 10 years, VMBS has outperformed GNMA with an annualized return of 1.41%, while GNMA has yielded a comparatively lower 1.24% annualized return.

VMBS

• 1D: 0.21%
• 1M: -1.57%
• YTD: 0.41%
• 6M: 2.06%
• 1Y: 5.79%
• 3Y*: 4.29%
• 5Y*: 0.49%
• 10Y*: 1.41%

GNMA

• 1D: 0.05%
• 1M: -1.75%
• YTD: 0.22%
• 6M: 2.07%
• 1Y: 5.33%
• 3Y*: 3.97%
• 5Y*: 0.40%
• 10Y*: 1.24%

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

VMBS vs. GNMA - Expense Ratio Comparison

VMBS has a 0.04% expense ratio, which is lower than GNMA's 0.15% 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%.

GNMA

iShares GNMA Bond ETF

VMBS

Vanguard Mortgage-Backed Securities ETF

Return for Risk

VMBS vs. GNMA — Risk / Return Rank

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

VMBS

VMBS Risk / Return Rank: 68
VMBS Sharpe Ratio Rank: 69
VMBS Sortino Ratio Rank: 68
VMBS Omega Ratio Rank: 60
VMBS Calmar Ratio Rank: 77
VMBS Martin Ratio Rank: 64

GNMA

GNMA Risk / Return Rank: 63
GNMA Sharpe Ratio Rank: 64
GNMA Sortino Ratio Rank: 65
GNMA Omega Ratio Rank: 55
GNMA Calmar Ratio Rank: 73
GNMA Martin Ratio Rank: 58

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.

VMBS vs. GNMA - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Mortgage-Backed Securities ETF (VMBS) and iShares GNMA Bond ETF (GNMA). 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.

	VMBS	GNMA	Difference
Sharpe ratio Return per unit of total volatility	1.16	1.12	+0.04
Sortino ratio Return per unit of downside risk	1.67	1.63	+0.04
Omega ratio Gain probability vs. loss probability	1.21	1.20	+0.01
Calmar ratio Return relative to maximum drawdown	1.95	1.88	+0.07
Martin ratio Return relative to average drawdown	6.10	5.60	+0.50
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

VMBS vs. GNMA - Sharpe Ratio Comparison

The current VMBS Sharpe Ratio is 1.16, which is comparable to the GNMA Sharpe Ratio of 1.12. The chart below compares the historical Sharpe Ratios of VMBS and GNMA, 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

	VMBS	GNMA	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.16	1.12	+0.04
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.07	0.06	+0.01
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.26	0.24	+0.02
Sharpe Ratio (All Time) Calculated using the full available price history	0.46	0.25	+0.21

Correlation

The correlation between VMBS and GNMA is 0.67, which is considered to be moderate. This suggests that the two assets have some degree of positive relationship in their price movements. Moderate correlation can be acceptable for portfolio diversification, offering a balance between risk and potential returns.

Dividends

VMBS vs. GNMA - Dividend Comparison

VMBS's dividend yield for the trailing twelve months is around 4.23%, which matches GNMA's 4.21% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
VMBS Vanguard Mortgage-Backed Securities ETF	4.23%	4.20%	3.94%	3.31%	2.35%	1.02%	2.01%	2.77%	2.72%	2.16%	2.10%	2.12%
GNMA iShares GNMA Bond ETF	4.21%	4.19%	4.15%	3.43%	2.01%	0.64%	1.89%	2.61%	2.41%	2.15%	1.89%	1.50%

Drawdowns

VMBS vs. GNMA - Drawdown Comparison

The maximum VMBS drawdown since its inception was -17.47%, roughly equal to the maximum GNMA drawdown of -17.09%. Use the drawdown chart below to compare losses from any high point for VMBS and GNMA.

Drawdown Indicators

	VMBS	GNMA	Difference
Max Drawdown Largest peak-to-trough decline	-17.47%	-17.09%	-0.38%
Max Drawdown (1Y) Largest decline over 1 year	-3.00%	-2.93%	-0.07%
Max Drawdown (5Y) Largest decline over 5 years	-17.12%	-16.02%	-1.10%
Max Drawdown (10Y) Largest decline over 10 years	-17.47%	-17.09%	-0.38%
Current Drawdown Current decline from peak	-1.57%	-1.75%	+0.18%
Average Drawdown Average peak-to-trough decline	-2.51%	-3.69%	+1.18%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.96%	0.98%	-0.02%

Volatility

VMBS vs. GNMA - Volatility Comparison

Vanguard Mortgage-Backed Securities ETF (VMBS) has a higher volatility of 1.90% compared to iShares GNMA Bond ETF (GNMA) at 1.77%. This indicates that VMBS's price experiences larger fluctuations and is considered to be riskier than GNMA based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VMBS	GNMA	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.90%	1.77%	+0.13%
Volatility (6M) Calculated over the trailing 6-month period	2.89%	2.76%	+0.13%
Volatility (1Y) Calculated over the trailing 1-year period	5.00%	4.78%	+0.22%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.71%	6.56%	+0.15%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.37%	5.11%	+0.26%