Check out the companies making headlines before the bell. Berkshire Hathaway — Warren Buffett's conglomerate saw shares fall more than 1% in premarket after hitting a record high Friday. The decline came after Berkshire's operating earnings fell 14% in the first quarter , driven by a 48.6% plunge in insurance-underwriting profit. Buffett also surprised shareholders by announcing at Saturday's annual meeting his intention to step down as CEO by the end of the year. The board voted unanimously on Sunday to make Greg Abel president and CEO on Jan. 1, 2026 and for Buffett, 94, to remain as chairman. Streamers — Streaming companies fell after President Donald Trump announced a 100% tariff on movies produced outside of the U.S. in a Sunday Truth Social post to save the "dying" American movie industry. Netflix declined 5%, Disney shed 3%, while Warner Bros. Discovery , Paramount and Amazon respectively slipped 2%, 1% and 1%. United Airlines — The travel stock dipped 1%, giving back some of its 7% gain from Friday. United announced on Friday that it was cutting some of its flights out of Newark, N.J., citing staffing and technology issues at the airport. Howard Hughes Holding — The stock popped 8% after the real estate developer and activist investor Bill Ackman's Pershing Square said the fund will buy 9 million newly issued shares of Howard Hughes for $100 per share. The price represents a 48% premium to the stock's closing price on Friday. Sunoco — Shares ticked lower nearly 1% after Sunoco announced it plans to acquire Parkland Corp. The cash and equity deal is valued at $9.1 billion, a figure that includes assumed debt. Wolfspeed — The semiconductor stock popped 7%, adding onto its Friday rally of 24%. Shares soared after Wolfspeed last week reaffirmed its third-quarter guidance and announced that executive vice president and chief financial officer Neill Reynolds would be concluding his position. Loews — The luxury hospitality stock rose 0.6% after the company reported first-quarter earnings of $1.74, which came below last year's figures of $2.05. However, Loews posted revenue of $4.49 billion, which was 6% higher versus the year-ago number of $4.23 billion. — CNBC's Michelle Fox, Alex Harring, Yun Li and Jesse Pound contributed reporting.