The surge in Atreca's stock price and trading volume is likely due to investors reacting to the company's recent corporate changes and regulatory issues. The termination of the lease at its corporate headquarters and the departure of the CFO could be seen as a sign of instability, which may have initially driven the stock price down. However, the company's decision to find a new location that suits its current needs and the CEO assuming the role of principal financial officer could be seen as positive steps towards restructuring and stability, which may have contributed to the stock price increase. The noncompliance notice from Nasdaq could also have sparked investor interest, leading to the heavy trading volume.