News reports said Russia had ended military exercises near Ukraine.
The Dow Jones industrial average (^DJI) rose 185 points, or 1.1 percent, to close at 16,553 Friday.
The Standard & Poor's 500 (^GSPC) index rose 22 points, or 1.2 percent, to 1,931. The Nasdaq composite (^IXIC) rose 35 points, or 0.8 percent, to 4,370.
The gain in the S&P 500 was the biggest since March 4 and turned the index higher for the week.
Lululemon (LULU) rose 3 percent after the company's founder agreed to sell half his stake as part of a deal to avert a battle for control.
Bond prices fell. The yield on the 10-year Treasury note edged up to 2.42 percent.