Mumbai, Feb. 3 -- The US stocks gained on Monday. The major averages all moved to the upside on the day following mixed outing in last week as supportive economic cues boosted sentiments. The Dow soared 515.19 points or 1.1 percent to 49,407.66, the Nasdaq climbed 130.29 points or 0.6 percent to 23,592.11 and the S&P 500 added 37.41 points or 0.5 percent to 6,976.44. Markets edged up as a report from the Institute for Supply Management showed that manufacturing activity in the US expanded for the first time in 12 months in January. The ISM said its manufacturing PMI jumped to 52.6 in January from 47.9 in December, with a reading above 50 indicating growth. Sentiments were also supported on reports Iran is prepared to negotiate with the US...