The bill provided 700 billion dollars to buy hard-to-value securities from banks.

VOA: special.2009.01.02

When they created margin rules that the seller had to be borrowing against securities. Just made more money when securities went up more value.

当我们发明保证金制度,卖空证券时需要交担保金,证券升值时能赚到更多钱。

斯坦福公开课 - 经济学课程节选

The central bank also announced that it would purchase up to $750 billion of additional mortgage-backed securities, which lost value with the collapse of the U.S.housing market.

VOA: standard.2009.03.18