Bank stocks rose Monday on optimism that efforts to revive economies worldwide will bolster results.

The U.S. banks' positive comments helped push the KBW Bank Index <.BKX> of large U.S. lenders up 37.4 percent last week. Barclays Capital analyst Jason Goldberg said it was the biggest gain in the index's history.

Stocks were also lifted after finance chiefs from the Group of 20 nations over the weekend pledged to bolster efforts to help economies, and Federal Reserve Chairman Ben Bernanke said the U.S. economy will probably emerge from recession this year and grow in 2010.

The news from Barclays is certainly helping, said Art Hogan, chief market analyst at Jefferies & Co in Boston. The rise in financials has given us a nice 10 percent move (from recent lows) in the market. It's something we can build on.

Before the positive comments, analysts had expected Bank of America and Citigroup to post first-quarter losses -- the second straight quarterly deficit for Bank of America and the sixth straight for Citigroup.

In morning trading, Bank of America shares rose 7.5 percent to $6.19, JPMorgan rose 1.3 percent to $24.06, Citigroup rose 9 percent to $1.94, and Wells Fargo & Co rose 2.7 percent to $14.32. The KBW index was up 2.4 percent, though it has still lost roughly two-fifths of its value this year.

(Reporting by Jonathan Stempel; Additional reporting by Ellis Mnyandu; editing by John Wallace)