The Treasury Market Practices Group late last week clarified its recommended fails charge trading practice for agency MBS to limit the scope to pass-throughs, where fails are most likely to happen. The agency debt and agency MBS trading practice has been updated to reflect the TMPGs recommendation that a fails charge apply to agency pass-through MBS issued or guaranteed by Fannie Mae, Freddie Mac and Ginnie Mae, the group said. The original recommendation was that the charge apply to agency MBS issued or backed by Fannie, Freddie and Ginnie Mae, which also issue most REMICs backed by agency pass-throughs. The TMPG has not...