QE2 had one undeniable effect though. It caused investors to go crazy with misconception. And much of this was implemented with borrowed dollars. NYSE margin debt soared throughout the program and declined by $10MM for the first time in June in anticipation of the program’s end. That loud sucking sound you heard in the market Wednesday was the margin calls that these traders are now receiving.
Margin Debt Declines With the End of QE2 - Seeking Alpha