Updated from 3:10 p.m. EDTFinancial stocks were among the worst performers of Monday's session following Bank of America's ( BAC) first-quarter earnings report, as credit deterioration remains a concern for U.S. banks. Bank of America reported a surprise first-quarter profit of $2.8 billion, or 44 cents, coming in well ahead of Wall Street's expectations. However, BofA said its provision for future credit losses jumped 57% to $13.4 billion, as nonperforming assets climbed to $25.7 billion, or 2.65% of the bank's book, from $18.2 billion, or 1.96% at the end of last year. Bank of America shares dropped 24.3% to close at $8.02 on Monday. Still, the stock is up 60% over the last three months and more than 100% since the beginning of March.