GNMA vs. MBSD

Last updated Apr 2, 2026

Compare and contrast key facts about iShares GNMA Bond ETF (GNMA) and FlexShares Disciplined Duration MBS Index Fund (MBSD).

GNMA and MBSD are both exchange-traded funds (ETFs), meaning they are traded on stock exchanges and can be bought and sold throughout the day. 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. MBSD is a passively managed fund by Northern Trust that tracks the performance of the ICE BofA Constrained Duration US Mortgage Backed Securities. It was launched on Sep 4, 2014. Both GNMA and MBSD 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

GNMA vs. MBSD - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares GNMA Bond ETF (GNMA) and FlexShares Disciplined Duration MBS Index Fund (MBSD). The values are adjusted to include any dividend payments, if applicable.

GNMA vs. MBSD - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
GNMA iShares GNMA Bond ETF	0.45%	8.25%	1.07%	5.34%	-10.83%	-1.86%	3.51%	5.85%	0.85%	1.74%
MBSD FlexShares Disciplined Duration MBS Index Fund	0.27%	7.12%	2.30%	4.46%	-9.49%	-1.40%	5.43%	6.05%	0.32%	0.86%

Returns By Period

In the year-to-date period, GNMA achieves a 0.45% return, which is significantly higher than MBSD's 0.27% return. Over the past 10 years, GNMA has underperformed MBSD with an annualized return of 1.27%, while MBSD has yielded a comparatively higher 1.48% annualized return.

GNMA

• 1D: 0.23%
• 1M: -1.26%
• YTD: 0.45%
• 6M: 1.88%
• 1Y: 5.35%
• 3Y*: 4.05%
• 5Y*: 0.45%
• 10Y*: 1.27%

MBSD

• 1D: -0.00%
• 1M: -0.84%
• YTD: 0.27%
• 6M: 1.31%
• 1Y: 4.30%
• 3Y*: 4.05%
• 5Y*: 0.52%
• 10Y*: 1.48%

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

GNMA vs. MBSD - Expense Ratio Comparison

GNMA has a 0.15% expense ratio, which is lower than MBSD's 0.20% 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%.

MBSD

FlexShares Disciplined Duration MBS Index Fund

GNMA

iShares GNMA Bond ETF

Return for Risk

GNMA vs. MBSD — Risk / Return Rank

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

GNMA

GNMA Risk / Return Rank: 59
GNMA Sharpe Ratio Rank: 61
GNMA Sortino Ratio Rank: 61
GNMA Omega Ratio Rank: 51
GNMA Calmar Ratio Rank: 69
GNMA Martin Ratio Rank: 54

MBSD

MBSD Risk / Return Rank: 59
MBSD Sharpe Ratio Rank: 60
MBSD Sortino Ratio Rank: 60
MBSD Omega Ratio Rank: 50
MBSD Calmar Ratio Rank: 74
MBSD Martin Ratio Rank: 53

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.

GNMA vs. MBSD - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares GNMA Bond ETF (GNMA) and FlexShares Disciplined Duration MBS Index Fund (MBSD). 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.

	GNMA	MBSD	Difference
Sharpe ratio Return per unit of total volatility	1.12	1.10	+0.02
Sortino ratio Return per unit of downside risk	1.63	1.59	+0.04
Omega ratio Gain probability vs. loss probability	1.20	1.20	0.00
Calmar ratio Return relative to maximum drawdown	1.90	2.08	-0.18
Martin ratio Return relative to average drawdown	5.64	5.43	+0.20
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

GNMA vs. MBSD - Sharpe Ratio Comparison

The current GNMA Sharpe Ratio is 1.12, which is comparable to the MBSD Sharpe Ratio of 1.10. The chart below compares the historical Sharpe Ratios of GNMA and MBSD, 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

	GNMA	MBSD	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.12	1.10	+0.02
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.07	0.10	-0.03
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.25	0.35	-0.10
Sharpe Ratio (All Time) Calculated using the full available price history	0.25	0.38	-0.13

Correlation

The correlation between GNMA and MBSD is 0.55, 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

GNMA vs. MBSD - Dividend Comparison

GNMA's dividend yield for the trailing twelve months is around 4.21%, less than MBSD's 4.26% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
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%
MBSD FlexShares Disciplined Duration MBS Index Fund	4.26%	4.23%	3.91%	3.39%	3.03%	2.41%	2.78%	3.42%	3.22%	3.30%	3.02%	3.46%

Drawdowns

GNMA vs. MBSD - Drawdown Comparison

The maximum GNMA drawdown since its inception was -17.09%, which is greater than MBSD's maximum drawdown of -14.36%. Use the drawdown chart below to compare losses from any high point for GNMA and MBSD.

Drawdown Indicators

	GNMA	MBSD	Difference
Max Drawdown Largest peak-to-trough decline	-17.09%	-14.36%	-2.73%
Max Drawdown (1Y) Largest decline over 1 year	-2.93%	-2.22%	-0.71%
Max Drawdown (5Y) Largest decline over 5 years	-16.02%	-14.10%	-1.92%
Max Drawdown (10Y) Largest decline over 10 years	-17.09%	-14.36%	-2.73%
Current Drawdown Current decline from peak	-1.52%	-1.34%	-0.18%
Average Drawdown Average peak-to-trough decline	-3.69%	-2.84%	-0.85%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.99%	0.85%	+0.14%

Volatility

GNMA vs. MBSD - Volatility Comparison

iShares GNMA Bond ETF (GNMA) has a higher volatility of 1.79% compared to FlexShares Disciplined Duration MBS Index Fund (MBSD) at 1.48%. This indicates that GNMA's price experiences larger fluctuations and is considered to be riskier than MBSD based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	GNMA	MBSD	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.79%	1.48%	+0.31%
Volatility (6M) Calculated over the trailing 6-month period	2.76%	2.28%	+0.48%
Volatility (1Y) Calculated over the trailing 1-year period	4.78%	3.93%	+0.85%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.56%	5.13%	+1.43%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.11%	4.25%	+0.86%