The Federal Reserve’s plan to purchase an additional $40 billion in agency MBS per month, above and beyond the $25 billion to $30 billion the Fed has been buying, will primarily benefit the agency MBS sector but could also spur revitalization of the non-agency market, analysts say. The open-ended plan, in effect until the U.S. economy and employment picture show significant improvement, adds some $480 billion in annual demand for agency MBS, a market that is on track to produce about $1.5 trillion in gross issuance. “The pressure on asset values to richen further will be substantial,” said analysts at Bank of America/Merrill Lynch. The additional MBS purchases and ongoing principal investments will...