The authority also ordered Oppenheimer to pay over $246,000 in restitution, plus interest, to clients who were charged unfair prices. In addition, FINRA fined Oppenheimer's head municipal securities trader, David Sirianni, $100,000 and has suspended him for 60 days. 

Between July 1, 2008, and June 30, 2009, Oppenheimer - via Sirianni - allegedly priced 89 client transactions from 5.01 per cent to 15.57 per cent above the firm's contemporaneous cost.

“Sirianni purchased municipal securities from a broker-dealer on Oppenheimer's behalf, held the bonds in inventory for at least overnight, and then made the bonds available for resale at an unfair price to the firm's customers. Sirianni was responsible for determining the prices paid by customers in the 89 transactions,” FINRA said.

It added: “Oppenheimer's supervisory system was deficient because supervisory personnel relied solely on a surveillance report that only captured intra-day transactions to review the fairness of markups/markdowns in municipal securities transactions.”

Oppenheimer and Sirianni neither admitted nor denied the charges, but consented to the entry of FINRA's findings.

At the end of August, US authorities charged a former portfolio manager at Oppenheimer with misleading investors about the valuation and performance of a fund consisting of other private equity funds (see here).