Niehaus resigned from his role at Jefferies after being suspended during the FCA investigation last year.
He admitted he should not have revealed the information and that he “did not know” why he had done it, other than to impress his friend and colleague.
In its final ruling, the FCA said: “Mr Niehaus’ conduct is particularly serious, given that some of the information disclosed related to a competitor of Client A.
“Mr Niehaus’ disclosure of client confidential information to a competitor could have conferred an undue advantage to Client A and demonstrates a failure to pay due regard to the interests of his client.”
The FCA reduced his penalty by 15% after Niehaus admitted the offences at the early interview.
The regulator also accepted that neither Niehaus nor the friends he shared the information with dealt in any securities relating to the messages.
