The improvements that the Federal Housing Finance Agency is expected to make to the government’s Home Affordable Refinance Program will likely come at the expense of MBS investors, say experts. The outlines of an expanded HARP are far from clear, but the FHFA is said to be giving serious consideration to lifting the 125 percent loan-to-value limit, in addition to waiving loan-level pricing adjustments, representation and warranties imposed on lenders, valuation requirements and the portability of mortgage insurance. The agency, which oversees Fannie Mae and Freddie Mac, is expected to make an...