Moderna’s stock retreated on Thursday after surging a record-setting 125% a day earlier, reducing the company’s market valuation by more than $18 billion to $51.5 billion from Wednesday’s close of $69.6 billion. Investors appeared to pull back after Moderna reported breakthrough trial results for a cancer vaccine. The rally briefly lifted co-founder Thomas Langer’s roughly 3% stake from $730 million on Tuesday to about $1.7 billion on Wednesday, making him a billionaire once again. Fellow co-founder Noubar Afeyan’s net worth rose $184 million to $2.2 billion, while CEO Stéphane Bancel’s fortune increased $2.5 billion to $5.8 billion. On Thursday, Afeyan’s net worth fell $105 million to $2.1 billion and Bancel’s declined $1.3 billion to $4.4 billion. Leerink Partners analyst Mani Foroohar wrote in June that Moderna’s late-stage cancer-vaccine trial could be a make-or-break event for the stock, with the experimental drug potentially working across multiple cancer types. Merck and Moderna are investigating the vaccine in trials for other cancers, including non-small-cell lung cancer and bladder cancer. Moderna’s business expanded sharply after the success of its mRNA-based COVID-19 vaccine, but the company reported a net loss of $782 million on revenue of $145 million through its latest quarter.