Check out the companies making headlines before the market opens. Talen Energy – Shares of the independent power company fell more than 8% after the Federal Energy Regulatory Commission rejected a request to increase power delivery from the Susquehanna nuclear plant to Amazon’s data center campus. Tallon owns the nuclear power plant and sold the data center campus to Amazon earlier this year. Shares of Constellation Energy and Vistra also fell about 9% and 3%, respectively. Investors expect Constellation and Vistra to announce similar arrangements with technology companies at some point. Viking Therapeutics – Shares soared 7% after the drugmaker announced promising results for its experimental VK2735 weight-loss drug, including up to 8.2% weight loss in four weeks. The drug is classified as GLP-1, which could put the company in competition with Novo Nordisk and Eli Lilly. Berkshire Hathaway – Shares of Warren Buffett’s conglomerate fell slightly after the company reported third-quarter operating profits totaling $10.1 billion. That was slightly below analysts’ expectations, according to FactSet. Apple – Warren Buffett’s Berkshire Hathaway reported earnings on Saturday morning and said it had sold off about a quarter of its shares, leaving only 300 million shares, causing the iPhone giant’s stock price to fall sharply by 0.6%. Berkshire Hathaway’s third-quarter operating profit totaled $10.1 billion, and its stock price fell slightly. That’s slightly below the FactSet consensus. Peloton – Shares of the fitness equipment company rose 8% after Bank of America upgraded its underperform rating to buy. The bank said Peloton is expected to achieve “substantial” growth in advance earnings under new CEO Peter Stern. Trump Media & Technology Group – Shares of former President Trump’s media company fell more than 3% ahead of the U.S. election on Tuesday. The stock has become increasingly volatile in the days leading up to the election. Roblox – The online gaming stock rose 3% after Morgan Stanley upgraded the stock to overweight from equal weight. The investment bank cited Roblox’s growing audience and said the stock is at a turning point. Vertex – Shares of Vertex rose 2.5% after Jefferies upgraded its rating on Vertex to buy from hold and said the tax software company has a long-term path to growth. The company also raised its price target by $15 to $50, implying an upside of nearly 20%. Nvidia, Sherwin-Williams – Shares of Nvidia and Sherwin-Williams rose nearly 2% and more than 4%, respectively, after they announced they would join the Dow Jones Industrial Average on November 8. Dow Corporation. Intel shares fell more than 1%, while Dow Chemical shares fell 0.6%. —CNBC’s Hakyung Kim, Brian Evans, Sarah Min, Lisa Kailai Han, Spencer Kimball, Tanaya Macheel and Michelle Fox Theobald contributed reporting.