WH Ireland Limited has been fined £1.2m by the FCA and has also been restricted from taking on new clients in its corporate broking division.
The restriction will last for 72 days.
The FCA has ruled that WH Ireland failed to ensure it had the proper systems and controls in place to prevent market abuse being detected, or occurring, between 1 January and 19 June 2013.
Within the period under question, the firm had around £2.5bn of assets under management and some 9,000 private wealth clients.
An FCA statement said: “These clients may have bought and sold financial instruments or may have been advised to do so by the firm without the necessary protections in place. WHI also had 87 corporate broking clients. Due to the lack of proper systems and controls in place, the firm could not protect against the risk of market abuse in respect of the information provided by these clients.”
Director of Enforcement and Market Oversight at the FCA Mark Steward said: “We expect all firms to have the right controls in place to mitigate risks and protect their clients and the integrity of the markets.
“In this case, WHI’s failings were aggravated by the failure to implement adequately the skilled person’s recommendations. It is one thing to be given a chance; for the chance not to be taken up is especially culpable.”