U.S. stocks booked their best weekly gains in several weeks, and the S&P 500 and Nasdaq finished at their highest levels since early October, as investors focused on progress on China trade talks and dismissed a batch of data that was less-than-stellar. The Dow Jones Industrial Average ended up 138 points, or 0.5%, at 25,849, finishing at its highest level since March 1. The S&P 500 index closed up 0.5% at 2,822, while the Nasdaq Composite Index finished up 0.8% at 7,688, with both indexes closed at their highest levels since Oct.