I still don't think it's trust. It's desperation. Equities aren't really in the same class as government bonds. But the holders of all this cash (I won't even call them investors, but rather folks left holding the bag after a gigantic monetary expansion) can't look to equities for a better rate, because in order for any instrument to provide a reliably high yield, the money supply would have to grow even faster, and it's already grown too fast.