A bottom-line bonanza for two more of the biggest U.S. banks reporting results Thursday. Quarterly profit at Bank of America more than doubled. Citigroup’s tripled. Like JPMorgan Chase and Wells Fargo, BofA and Citi unlocked billions of dollars from their reserves they had set aside to cover potential loan losses stemming from the health crisis. They’re betting the rapid vaccinations and massive government stimulus will help the economy bounce back. In a sign of confidence, Bank of America said it plans to buy back $25 billion worth of its shares. But challenges remain. Its consumer banking revenue and net interest income declined. Interest rates remain low, and that eats into the income of lenders like BofA. Loans and lease balances also fell. Like BofA, Citigroup’s consumer bank felt the impact of low rates. Loans declined 10% due to lower loan balances on consumer credit cards. Revenue fell as those low rates helped offset higher revenue from investment banking and equity markets. The bank also said it would divest its consumer businesses in China, Australia, India and 10 other markets in Asia, Europe and the Middle East. It’s the latest move by its new CEO Jane Frazer, who has launched a strategic review to boost shareholder returns. She said Citi lacked the scale to compete in those markets. Shares of Citigroup rose in early trading Thursday, but BofA fell.