China’s cyberspace administration said it had launched a new investigation into Didi to protect national security and the public interest.

Details: The announcement comes just two days after Didi began trading on the New York Stock Exchange. During the investigation, Didi was not allowed to register new users, the Cyberspace Administration of China (CAC) said.

The Chinese ride-hailing giant said in a statement that it will "fully cooperate" during the review period.

Didi’s debut on Wednesday was the biggest US listing by a Chinese company since Alibaba in 2014. 

Founded in 2012, Didi claims that its annual active users are 493 million and its average daily transaction volume is 41 million. It began to expand internationally in 2018, and the company currently operates in 14 countries outside of China.

Context: In recent years, China has tightened its supervision of tech giants. In June, regulators were investigating whether Didi violated antitrust laws. The giant had warned in its IPO prospectus that it met with regulators earlier this year, along with several other Chinese internet companies. The ride-hailing company said it might be subject to penalties, as regulatory bodies might not be satisfied with the inspection results.