A number of firms that hold vintage non-agency mortgage-backed securities are using their clean-up call options as the outstanding balance in the MBS dwindles. Executing clean-up calls can be more profitable for certain firms than allowing securities to run-off. Chimera Investment is the latest firm to tout its clean-up call strategy. The real estate investment trust said it acquired the rights to $4.8 billion of seasoned subprime mortgages by purchasing subordinate tranches of non-agency MBS issued by Springleaf Finance between 2011 and 2013. The purchase price wasn’t disclosed.