The gains Monday built on a massive rally on Friday, the latest big swing over the past three months. Companies that rely on consumer spending did especially well. Amazon jumped 3.4 percent, surpassing Microsoft as the most valuable publicly traded U.S. company.
Mattel jumped 7.7 percent after announcing a licensing deal with the South Korean boy band BTS. The S&P 500 rose 17 points, or 0.7 percent, to 2,549. The Dow Jones Industrial Average added 98 points, or 0.4 percent, to 23,531. The Nasdaq rose 84 points, or 1.3 percent, to 6,823.
Bond prices fell. The yield on the 10-year Treasury rose to 2.70 percent.
Stocks are turning higher in midday trading, led by retailers and smaller companies.
The gains Monday came after a report showed strong orders last month for service companies, which make up the bulk of the U.S. economy.
Investors were also keeping a close eye on a new round of trade talks between the U.S. and China.
Dollar Tree rose 5.8 percent after activist investor Starboard value disclosed a stake in the discount retailer and pushed the company to make changes.
The S&P 500 index rose 24 points, or 1 percent, to 2,556.
The Dow Jones Industrial Average added 146 points, or 0.6 percent, to 23,577. The Nasdaq rose 94 points, or 1.4 percent, to 6,833.
Bond prices fell. The yield on the 10-year Treasury note rose to 2.68 percent.
U.S. stocks are mixed as representatives from the U.S. and China start a new round of trade talks. Stocks endured huge swings over the past two days.
Retailers made some of the largest gains Monday. Discount retailer Dollar Tree jumped 3.7 percent after an activist investment firm said the company should consider selling its Family Dollar business.
Stocks are coming off a huge gain Friday following a big loss on Thursday as investors worried about issues including economic growth.
The S&P 500 index lost 2 points, or 0.1 percent, to 2,529.
The Dow Jones Industrial Average fell 51 points, or 0.2 percent, to 23,381.
The Nasdaq rose 10 points, or 0.2 percent, to 6,749.