Why is Sakura Internet stock sliding today?

Sakura Internet's stock plummeted 9.7% to ¥3,535 on Thursday after the company revealed the extent of a cybersecurity incident. The breach, which began on August 17, had initially been reported to involve rental server environments. However, the disclosure later showed unauthorized access had extended to an internal system used for managing customer contracts and billing information.

This new information potentially affects up to 1.36 million member accounts, significantly more than the initial 583 rental server accounts reported. While the company did not confirm data exfiltration at the time of the disclosure, the magnitude of the exposed data, including customer contracts and billing records, heightened concerns over the company's cybersecurity measures and the full scope of the damage. The stock dip coincided with a 0.8% rise in the Nikkei 225.