By Ryan Vlastelica
NEW YORK (Reuters) - U.S. stocks rose on Monday, with the S&P 500 on track to end the first quarter of 2014 with slight gains, after Federal Reserve Chair Janet Yellen calmed concerns about a rate hike coming earlier than expected.
Gains were broad, with nine of the S&P 500's 10 primary sectors rising on the day. Material stocks <.SPSMCM> were the biggest gainers, jumping 1.8 percent, while utility stocks <.SPSMCU> were up 1.6 percent.
Technology and financial shares, which along with materials are tied to the pace of economic growth, also outperformed on the day. Micron Tech
In her first public speech since becoming Fed chair two months ago, Yellen said that the U.S. central bank's "extraordinary" commitment to boosting the economy would be needed for some time to come.
Earlier this month, Yellen raised concerns by saying that the period between the end of the Fed's quantitative easing program and the first rate increase from the central bank could be six months, a faster timeline than many had anticipated.
"What Yellen did today was to alleviate that confusion and provide more clarity. When there aren't concerns about the Fed tightening, the market can breathe easier," said Joseph Tanious, global market strategist at J.P. Morgan Asset Management in New York.
Biotech stocks continued to be in focus following recent volatility when investors sharply took profits in the high-flying sector. The Nasdaq Biotechnology index <.NBI> jumped 2.7 percent, following a 7 percent decline last week, in what was the index's fifth consecutive weekly decline.
Among some of the more active names, Vertex Pharmaceuticals
The Dow Jones industrial average <.DJI> was up 136.83 points, or 0.84 percent, at 16,459.89. The Standard & Poor's 500 Index <.SPX> was up 14.44 points, or 0.78 percent, at 1,872.06. The Nasdaq Composite Index <.IXIC> was up 45.59 points, or 1.10 percent, at 4,201.35.
Equities also received a boost from end-of-quarter "window dressing," when money managers adjust positions to improve the look of their portfolios.
With Monday's advance, the S&P 500 is up 0.7 percent for the month and up 1.3 percent for the quarter, the benchmark index's fifth straight quarterly rise, though its worst quarterly performance since the last quarter of 2012.
The Dow is up 0.8 percent for the month but down 0.7 percent for the quarter. The Nasdaq is down 2.5 percent for March but up 0.6 percent for the quarter.
The Institute for Supply Management-Chicago business barometer was at 55.9 in March, its lowest level since August and down from 59.8 in February. Economists' median forecast in a Reuters poll was 59.0.
U.S.-listed shares of Prana Biotechnology Ltd
Logistics company UTi Worldwide Inc
(Editing by Bernadette Baum and Nick Zieminski)
