On Friday (December 22), Karuna Therapeutics, a US biopharmaceutical company listed on NASDAQ, rose 47% to $317.85 per share, breaking a historic high set in August last year, with a market value of $11.99 billion. Before the day's trading, veteran multinational biopharmaceutical giant Bristol Myers Squibb (BMS) and Karuna announced that the two companies had signed a final merger agreement. BMS agreed to acquire Karuna for $330 per share, with a total transaction value of $14 billion, expected to be completed in the first half of next year.