The Dow Jones industrial average was up 4.25 percent Thursday morning, its biggest weekly gain since the start of the year.
The Dow rose 12.93 points, or 0.3 percent, to 20,966.83.
The S&P 500 rose 2.51 points, to 2,976.62.
The Nasdaq composite rose 1.97 points,, to 6,099.97.
The Russell 2000 index was down 2.06 points, at 4,814.30.
The Nasdaq Composite dropped 2.09 points, by 4,084.89.