Wall Street closed out another erratic week with a big gain today after investors took comments from President George W Bush and Federal Reserve Chairman Ben Bernanke as reassuring signs Wall Street won’t be left to deal with problems in the mortgage and credit markets on its own.

Wall Street closed out another erratic week with a big gain today after investors took comments from President George W Bush and Federal Reserve Chairman Ben Bernanke as reassuring signs Wall Street won’t be left to deal with problems in the mortgage and credit markets on its own.

A brokerage downgrade of several semiconductor companies pressured tech shares in New York today, while the broader market was little changed as a jump in jobless claims offset investors’ relief over declining oil prices.