Alibaba’s US-listed shares slump 13%, biggest one-day drop since debut

Alibaba Group Holding’s U.S.-listed shares witnessed the biggest ever fall after China on Thursday announced that it would launch a probe into the company’s alleged monopolistic practices.

The stock fell 13% in its biggest one-day drop on record. The decline took Alibaba to its lowest level since July, and the stock is now down 30% from an October peak. Roughly 141 million shares exchanged hands, the most for a single session since its 2014 debut. On Thursday, Alibaba slid 8% in Hong Kong to a five-month trough.

The Chinese government on Thursday launched a probe into Alibaba’s alleged monopolistic practices. Affiliate Ant Group Co., the other pillar of billionaire Jack Ma’s internet empire, was also summoned to a high-level meeting over financial regulations. The pressure on Ma is central to China’s broader effort to rein in an increasingly influential internet sphere