NEW YORK, March 31 (Reuters) - U.S. stocks rose on Monday, with the S&P 500 ending both March and the first quarter of 2014 with gains, after Federal Reserve Chair Janet Yellen calmed concerns about a rate hike coming earlier than expected.
On Monday, the Dow Jones industrial average rose 134.60 points, or 0.82 percent, to end unofficially at 16,457.66; the S&P 500 added 14.72 points, or 0.79 percent, to finish unofficially at 1,872.34, and the Nasdaq Composite gained 43.24 points, or 1.04 percent, to close unofficially at 4,198.99.
For March, the Dow rose 0.8 percent and the S&P 500 gained 0.7 percent, while the Nasdaq lost 2.5 percent.
For the first quarter, the Dow fell 0.7 percent, while the S&P 500 climbed 1.3 percent and the Nasdaq gained 0.5 percent.
Reporting by Rodrigo Campos; Editing by Jan Paschal