US stocks falter after three-day rally

U.S. stocks vacillated between small gains and losses on Friday, trying to extend a three-day winning streak, as investors analyzed earnings reports from Twitter and other companies.

The S&P 500 fell 0.1%, a day after the broad benchmark jumped 1%. The Dow Jones Industrial Average rose 0.2%, recently adding 60 points, and the Nasdaq Composite fell 0.6%.