Warren Buffett's Berkshire Hathaway recently capitalized on a December market sell-off, purchasing over $560 million in stocks. The firm acquired over 8 million shares of Occidental Petroleum, raising its stake to over 28. Berkshire also purchased 5 million shares of Sirius XM, bringing its ownership to approximately 35. Berkshire acquired shares of VeriSign for $45 million, a smaller investment in a tech stock that has declined 6 this year. Buffett leveraged the market pullback to expand these holdings.