Government Agency MBS United States GNMA iShares GNMA Bond ETF 4 2 2 0.001 MBB iShares MBS ETF 4 2 2 0.001 MBG SPDR Bloomberg Barclays Mortgage Backed Bond ETF 4 2 2 0.001 MBSD FlexShares Disciplined Duration MBS Index Fund 4 2 2 0.001 VMBS Vanguard Mortgage-Backed Securities ETF 4 2 2 0.001