The all-time high Thursday came after solid results from a number of U.S. companies including Mylan, a drug maker, and several retailers.
The S&P 500 has fallen just short of a record the previous three days.
On Thursday, the index increased nine points, or 0.5 per cent, to 1,854, beating its Jan. 15 record by six points.
The Dow Jones industrial average rose 74 points, or 0.5 per cent, to 16,272. The Nasdaq climbed 26 points, or 0.6 per cent, to 4,318.
J.C. Penney jumped 25 per cent after the department store operator swung to a profit in the fourth quarter after posting a big loss in the same period a year earlier.