OREANDA-NEWS. Robinhood Markets, which owns the Robinhood securities trading app, popular among US retail investors, has reported a major data breach.

The company said in a statement that the hack occurred on 3 November, when a fraudster called customer service and persuaded a member of staff to provide him with the data needed to access the department's systems.

According to the company, the criminal had acquired the e-mail addresses of about 5 million people, the full names of 2 million other customers, as well as the names, dates of birth, postal addresses and account details of about 300 other users.

Robinhood said no "sensitive" information, such as national insurance numbers, bank account or credit card details, was stolen and no financial losses were incurred by clients of the service.

The hacker demanded a ransom from Robinhood and the company notified law enforcement authorities about the incident. Mandiant, which specializes in cybersecurity, took over the investigation.

As The Wall Street Journal notes, there are 22.4 million active brokerage accounts on the Robinhood platform. Thus, the theft affected nearly a third of the company's customers.

Robinhood shares were down in the postmarket session on November 8, quotations fell by 3.4% while the main session ended with an increase of 2.6%.