Check out the companies making headlines before the bell. Talen Energy â The independent power company tumbled more than 8% after the Federal Energy Regulatory Commission rejected a request to increase the amount of power the Susquehanna nuclear plant can dispatch to an Amazon data center campus. Talen owns the nuclear plant and sold the data center campus to Amazon earlier this year. Constellation Energy’s and Vistra’s stocks fell about 9% and 3%, respectively, in sympathy. Constellation and Vistra were expected by investors to announce similar arrangements with tech companies at some point. Viking Therapeutics â The drugmaker soared 7% after announcing promising results from its experimental VK2735 obesity pill, including weight loss of up to 8.2% within a four-week period. The drug is classified as a GLP-1, which could put the company in competition with Novo Nordisk and Eli Lilly. Berkshire Hathaway â Shares were marginally lower after Warren Buffett’s conglomerate revealed that operating earnings totaled $10.1 billion in the third quarter . This was slightly below what analysts had expected, according to FactSet. Apple â The iPhone behemoth saw shares dip 0.6% on heavy volume after Warren Buffett’s Berkshire Hathaway reported its earnings Saturday morning and indicated that it dumped approximately a quarter of its stake , with just 300 million shares remaining in the holding. Berkshire Hathaway shares were marginally lower after operating earnings totaled $10.1 billion in the third quarter. This was slightly below the FactSet consensus. Peloton â Shares of the exercise equipment company popped 8% following an upgrade at Bank of America to buy from underperform . The bank said it sees “many miles” of earnings before interest, taxes, depreciation, and amortization growth under Peloton’s new CEO Peter Stern, who starts in January. Trump Media & Technology Group â Shares of former President Donald Trump’s media company pulled back more than 3% ahead of the U.S. election on Tuesday. The stock has been increasingly volatile in the days leading up to the election . Roblox â The online game stock jumped 3% after Morgan Stanley upgraded shares to overweight from equal weight . The investment bank cited Roblox’s growing audience and says the stock is at an inflection point. Vertex â Shares rose 2.5% after Jefferies upgraded Vertex to buy from hold , saying the tax software company has a runway for long-term growth. The firm also hiked its price target by $15 to $50, implying nearly 20% upside. Nvidia , Sherwin-Williams â Shares of Nvidia and Sherwin-William rose nearly 2% and more than 4%, respectively, following the announcement that both names are set to join the Dow Jones Industrial Average , effective Nov. 8. Nvidia is set to replace rival chipmaker Intel , and Sherwin-Williams will replace Dow Inc . Shares of Intel were more than 1% lower, while Dow Inc. shares were off 0.6%. â CNBC’s Hakyung Kim, Brian Evans, Sarah Min, Lisa Kailai Han, Spencer Kimball, Tanaya Macheel and Michelle Fox Theobald contributed reporting.