Subprime mortgage bond losses may be nearing the end, according to a published report Friday citing Standard & Poor's chief credit officer Mark Adelson. The S&P exec said losses are being "double counted" by many because so much private-party subprime MBS is held by CDOs, and suggested true subprime losses would total roughly $550 billion. That total is roughly half the value of all first-mortgage subprime debt issued since 2005, Bloomberg News reported. The news service said that subprime-led losses already total $508.5 billion, meaning that subprime losses may not have much further to run -- or that Adelson is incorrect. Take your pick. Adelson told Bloomberg that the term "subprime securities" has been used indiscriminately to refer to both CDOs and first-lien subprime mortgage asset-backed securities. While many top-rated parts of the CDOs may default, only a few AAA-rated subprime asset-backed securities will, he suggested. He also noted that the huge market for credit-default swaps that was created around subprime bonds don't really count. "You can't lose the same dollar more than once," he told Bloomberg. Irrespective of his specific take on subprime MBS, nobody should construe Adelson's remarks as meaning the credit crunch is over; by now, it's clear that financial market problems and the general mortgage malaise spread well beyond subprime MBS, and are hitting portfolioed loans and other loan classes as well. Related links: Standard and Poor's report