Stocks are closing at record highs as investors are encouraged by the latest sign that the job market is improving, the AP reports. Payroll processor ADP said Thursday that private companies added more jobs last month than investors expected. Banks and health care companies posted big gains. Wells Fargo rose 1.8% and UnitedHealth Group rose 2.5%. The Standard & Poor's 500 index gained 18 points, or 0.8%, to 2,430. The Dow Jones industrial average rose 135 points, or 0.7%, to 21,144. The Nasdaq composite climbed 48 points, or 0.8%, to 6,246. All three closed at all-time highs. Small-company stocks rose more than the rest of the market. The Russell 2000 index rose 25 points, or 1.9%, to 1,396. (More stock market stories.)