On Thursday, S&P hiked its estimate on mortgage writedowns by banks to USD 285 billion, but it said the end may be in sight. This is the amount S&P expects banks to record as "write-downs," or assumptions that their investments are no longer as valuable. Banks including Citigroup Inc, Merrill Lynch & Co. have written off over USD 150 billion of investments, in part because they are backed by home loans considered unlikely to be repaid.

S & P's previous estimate for write-downs was USD 265 billion. The ratings agency said Wall Street is likely more than halfway through the write-downs it will have to record. "The positive news is that, in our opinion, the global financial sector appears to have already disclosed the majority of valuation write-downs of subprime asset-backed securities," S&P credit analyst Scott Bugie said in a report.