Shares of ALAB surged about 12%, or roughly $9, in U.S. pre-market trading on Monday as traders pointed to a wave of out-of-the-money call-option buying that accelerated ahead of the open. The company had not issued any material news as of the time of the move, and the catalyst for the buying remained unclear. The spike in ALAB options activity came alongside broader pockets of unusual call volume highlighted by market monitors in other names, including Invesco, Opendoor and Embraer.