NEW YORK (Reuters) - U.S. homebuilding stocks rose on Monday, boosted by data that showed homebuilder sentiment rose in August to its highest level since January. Sentiment rose as labor market conditions improved, according to the National Association of Home Builders data. The NAHB/Wells Fargo Housing Market index rose to 55 in August from 53 in July, the group said in a statement. It was the third straight monthly gain, and topped the mean estimate of analysts polled by Reuters for a reading of 53. Following the data, the PHLX Housing index <.HGX> rose 1.5 percent, more than twice the advance of the S&P 500's <.SPX> 0.7 percent rise. PulteGroup Inc was one of the S&P's biggest percentage gainers, up 2.3 percent to $18.69. Among other names, D.R. Horton Inc rose 1.8 percent to $21.21, Toll Brothers gained 2.1 percent to $34.69 and Beazer Homes added 2.7 percent to $17.77. The SPDR S&P Homebuilders exchange-traded fund rose 1.7 percent to $21.12. The U.S. dollar index <.DXY> rose 0.2 percent, with gains accelerating after the data was released. Readings below 50 mean more builders view market conditions as poor than favorable. "Each of the three components of the HMI registered consecutive gains for the past three months, which is a positive sign that builder confidence appears to be firming following an uneven spring," said NAHB Chief Economist David Crowe. "Factors contributing to this rise include sustained job growth, historically low mortgage rates and affordable home prices, which are helping to unleash pent-up demand." The single-family home sales component rose to 58 from a revised 56 and was also the highest reading since January. The gauge of single-family sales expectations for the next six months rose to 65, the highest since August 2013, while prospective buyer traffic rose from 39 to 42, the highest since December. (Reporting by Ryan Vlastelica; Editing by Meredith Mazzilli)