Dow soars on service sector expansion

The service sector grew for the first time in more than a year, helping stocks post sharp gains Monday.

The Institute for Supply Management said its services index rose to 50.9 in September from 48.4 in August. Any reading above 50 indicates growth. Economists polled by Bloomberg News expected the services index to total 50 in September. It hit a low of 37.4 in November.

The blue-chip Dow Jones Industrial Average ($INDU) responded by jumping 112 points, or 1.2 percent, to close at 9,600, while the broader S&P 500 ($INX) gained 15 points, or 1.5 percent, to 1,040. The tech-heavy Nasdaq Composite ($COMPX) added 20 points, or 1 percent, to finish at 2,068.