Call it the Bernanke boost. Stocks, climbing for a week, got an extra jolt after the Fed chairman said the central bank will keep supporting the economy. The Dow and S&P 500 hit record highs. The 10-year Treasury note’s yield continued to fall as investors bought bonds. Stocks that benefit most from low interest rates, such as home builders, notched big gains. Late Wednesday, Bernanke said the economy needs the Fed’s easy-money policy ‘for the foreseeable future.’ Stocks surged when the market opened Thursday. ‘It’s back to the old accommodative Fed, so the markets are happy again,’ said Randy Frederick, at the Schwab Center.