New regulatory filings showed that Warren Buffett ‘s Berkshire Hathaway doubled its position in beer and wine producer Constellation Brands last quarter. But at least one investor doesn’t agree with the “Oracle of Omaha’s” investment. Main Street Research’s Chief Investment Officer James Demmert joined CNBC’s ” Power Lunch ” on Friday to offer his take on two Buffett trades, alongside one other market mover. Here is what he had to say during the show’s “Three-Stock Lunch” segment. Constellation Brands Berkshire doubled its stake in Constellation Brands last quarter, increasing the value of the position to around $2.2 billion. Shares of Constellation Brands, which imports all of its beer from Mexico , have stumbled 11% this year as President Donald Trump’s steep tariffs on Mexican imports threatened its bottom line. The stock added nearly 3% on Friday after Berkshire disclosed its position. But Demmert is skeptical of Buffett’s bet. “We don’t think the stars align for Constellation,” he said. “The company expects a billion-dollar hit from tariffs just this year alone. Stock’s down. … Let’s remember this is a lower margin business, and there’s a growing trend of nonalcoholic mocktail drinkers that can have an impact. We’re a seller.” Citigroup With Citigroup , too, Demmert diverges from Buffett. While Berkshire sold out of its Citigroup position by the end of March, Demmert said he was a “big buyer” of the bank stock. “Investors should overweight financials in general, and for the same reasons, we own Citigroup,” he said. “Valuation’s at nine times earnings, which is cheap. They’ve got increasing [investment] bank and trading revenue deregulation, tailwinds are coming their way. And let’s face it, the financials are tariff immune. So is Citi.” Shares of Citi have climbed 7% in 2025. Novo Nordisk Novo Nordisk ‘s stock slumped 3% on Friday after CEO Lars Fruergaard Jørgensen announced he would step down from his position , citing recent market challenges. Jørgensen, who held the position for the past eight years, will remain at the helm “for a period to support a smooth transition to new leadership” as Novo Nordisk searches for a successor. But this leadership transition wasn’t enough to convince Demmert the stock was a buy. He said he still sees Novo Nordisk’s market share losses to rival GLP-1 medication producer Eli Lilly as a major headwind for the stock. “Lilly’s taken their market share and had their lunch with it. Stock’s down 52%. The company’s fired the CEO, I think, to get a reaction from Wall Street,” Demmert said. “It’s a value trap. It’s a sell.”
