Online trading app Robinhood has confirmed that a data breach occurred on November 3, 2021. the incident has reportedly affected 5 million of Robinhood’s clients.

For approximately 310 traders, the breach was more serious, as it affected additional personal information, including name, date of birth, and zip code, was exposed, with a subset of approximately 10 customers having more extensive account details revealed.

Below is the full statement by the company:

Late in the evening of November 3, we experienced a data security incident. An unauthorized third party obtained access to a limited amount of personal information for a portion of our customers. Based on our investigation, the attack has been contained and we believe that no Social Security numbers, bank account numbers, or debit card numbers were exposed and that there has been no financial loss to any customers as a result of the incident.

The unauthorized party socially engineered a customer support employee by phone and obtained access to certain customer support systems. At this time, we understand that the unauthorized party obtained a list of email addresses for approximately five million people, and full names for a different group of approximately two million people. We also believe that for a more limited number of people—approximately 310 in total—additional personal information, including name, date of birth, and zip code, was exposed, with a subset of approximately 10 customers having more extensive account details revealed. We are in the process of making appropriate disclosures to affected people.

After we contained the intrusion, the unauthorized party demanded an extortion payment. We promptly informed law enforcement and are continuing to investigate the incident with the help of Mandiant, a leading outside security firm.

“As a Safety First company, we owe it to our customers to be transparent and act with integrity,” said Robinhood Chief Security Officer Caleb Sima. “Following a diligent review, putting the entire Robinhood community on notice of this incident now is the right thing to do.”

If you are a customer looking for information on how to keep your account secure, please visit Help Center > My Account & Login > Account Security. When in doubt, log in to view messages from Robinhood—we’ll never include a link to access your account in a security alert.