As powerful as it may be, the Fed is not the market. And since the Fed failed to restore trust in the system by forcing all bad debts to light, the financial world has grown increasingly volatile and broken as investors grow increasingly distrustful of the system and begin to pull their money from it: see market volumes continuing to plunge.
Nowhere is the lack of trust more apparent than in the financial sector. Indeed, it was a lack of trust between banks (inter-bank lending) that caused the credit markets to jam up in 2008, which resulted in the Crash.
That lack of trust continues to this day. In the post-Lehman collapse, instead of forcing real derivative and credit risk out into the open, the Federal Reserve and regulators instead suspended accounting standards and allowed financial firms (and other corporate entities) to continue to lie about the true state of their balance sheets.
As a result of this, the financial sector remains rife with fraud and impossible to accurately value (how can you value a business that is lying about its balance sheet?).