Reuters
The arrests occurred in the past few months and will be followed by more, according to Bloomberg.
The
A spokeswoman for the FCA declined to comment.
In May, two men, including a former managing director at Deutsche Bank, were found guilty in the UK's biggest-ever insider trading case.
Martyn Dodgson, the former managing director, and Andrew Hind, an accountant, were convicted by a London jury on Monday after a trial that lasted 12 weeks.
Three other defendants - Grant Harrison, a former managing director at Altium Capital, day trader Benjamin Anderson and former Aria Capital director Iraj Parvizi - were found not guilty.
The convicted men face a maximum of seven years in prison and a sentencing verdict could come as soon as this week.
They were accused of generating more than £7 million in profit, trading on inside information on stocks such as Legal & General, Scottish & Newcastle, and Sky.