Why Is Atreca (BCEL) Stock Up 85% Today?

Group 1 - Atreca (NASDAQ:BCEL) stock is experiencing a significant rise due to Baker Bros. Advisors LP acquiring a 19.9% stake in the company [1] - The stake acquisition includes a combination of Class A shares and Class B shares, with Class B shares convertible to Class A shares [1] - The conversion of Class B shares to Class A shares will be limited to a 19.99% stake and will take effect on February 21, 2024 [1] Group 2 - Heavy trading activity is noted for BCEL stock, with over 20 million shares traded, significantly exceeding the average daily volume of approximately 2.6 million shares [2] - As of Thursday morning, BCEL stock has increased by 84.6% [2]