The Dow and the S&P 500 hit record highs during Thursday's trading day and at the close. Investors were cheered by some strong corporate earnings reports, encouraging data on the job market, and reassurances from the head of the U.S. central bank.
A Labor Department report showed the number of Americans signing up for unemployment assistance dropped to its lowest level in two months. Jobless claims fell 24,000 to a nationwide total of 334,000.
Economists use unemployment insurance claims to track layoffs, and they say declining claims mean a strengthening job market.
Wednesday and Thursday, U.S. Federal Reserve Chairman Ben Bernanke told Congress that efforts to stimulate the economy will continue until improved growth shows they are no longer needed. That may mean that the Fed's program of buying billions of dollars in securities each month will not be cut back until later this year, and very low short-term interest rates could stay in place until sometime next year.