Teva Pharmaceutical shares jumped 11 percent after Berkshire Hathaway reported a $358 million stake.
Berkshire Hathaway reported holding 18.9 million ADRs of Teva. After spiking, Teva was still up more than 6 percent in after-hours trading.
Berkshire also reported a 23.3 percent increase in its holdings of Apple shares, to 165 million, and a 21 percent increase in its holdings of Bank of New York Mellon, to 60.8 million shares.
At the same time, Berkshire has cut its holdings of IBM 94 percent, to just over 2 million shares. It also trimmed its Wells Fargo stake by 6 million shares to 458 million, and its stake in General Motors by 10 million shares, to 50 million.