Updated from 9:39 a.m. ESTStocks on Wall Street were in a slump Tuesday morning, as financial firms were working to accommodate strains on homeowners, U.S. automakers fumbled for answers to a stark business outlook and corporate earnings statements remained lackluster. The Dow Jones Industrial Average lost 237 points to 8633, and the S&P 500 fell 26 points to 893. The Nasdaq gave back 40 points to 1577. Among stocks in the news, Citigroup ( C) said it would alter terms for mortgages to avoid foreclosure proceedings on as much as $20 billion in at-risk home loans. Last Friday, JPMorgan Chase ( JPM) announced a similar mortgage-refinance program, covering $110 billion in loans. Bloomberg also reported that government-controlled mortgage companies Fannie Mae ( FNM) and Freddie Mac ( FRE) were planning similar mortgage-restructuring initiatives. The decision by big banks to refinance mortgages is about a year overdue, said Michael Church, portfolio manager at Church Capital. Although it's much cheaper for banks when they avoid foreclosing on homes, securitization of mortgages has made it difficult to find out who the end-borrowers and the end-lenders are. "With things on a massive scale like this, I'm not surprised it has taken a year," he said. Meanwhile, credit card company American Express ( AXP) got the go-ahead from the Federal Reserve to turn itself into a bank holding company. Such a move would allow American Express to build a deposit base and secure Fed funding. Goldman Sachs ( GS) and Morgan Stanley ( MS) had earlier this year successfully petitioned the Fed for bank holding company status. Separately, the Los Angeles Times reported that Goldman Sachs had been encouraging its clients to bet against California bonds even as it was collecting fees to help California sell the same bonds.