The almost two-year long US housing slump and a related credit squeeze have dried up cash flows supporting the global banking network.
The benchmark Dow Jones Industrial Average closed up 41.13 points (0.31 percent) at 13,473.90. The blue-chip index had soared over 200 points and then declined before recovering ground in late afternoon trading.
The tech-rich Nasdaq composite finished up 18.79 points (0.71 percent) at 2,671.14 while the broad-market Standard & Poor's 500 index gained 8.94 points (0.61 percent) to close at 1,486.59.
"Finally, the central banks to the rescue," Sherry Cooper, a chief economist at BMO Capital Markets, said in a briefing note to investors calling the effort "the biggest act of global economic cooperation since September 1