Well, we know that State Street sold a lot of MBS, but it's still a bit confusing, given they're supposed to be re-investing the proceeds into USTs. The other culprit is, apparently, the Japanese MOF that's been selling non-stop.
http://www.bloomberg.com/news/2010-...n-mortgage-debt-takes-350-million-charge.html
http://www.bloomberg.com/news/2010-...n-mortgage-debt-takes-350-million-charge.html

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