Bank plan skepticism sinks Wall Street

Stocks tumbled on Tuesday with the Dow and the S&P 500 down more than 4 percent, as bank shares slid on concerns that a plan to shore up the financial sector may not be enough to loosen up credit and contain the deepening recession.

Indexes slumped immediately following Treasury Secretary Timothy Geithner's announcement of a plan to mop up $500 billion in spoiled assets from the beleaguered banking system.

Financial stocks, which had spearheaded a rise in the market in recent sessions in anticipation of the plan, skidded as the lack of details in Treasury's announcement raised questions about whether the plan will be enough to rein in the financial crisis.

The KBW Banks index tumbled 12.2 percent and the S&P financial index slid 8.9 percent.