The U.S. Securities and Exchange Commission has filed a lawsuit accusing unnamed defendants of insider trading in Onyx Pharmaceuticals call options before the drugmaker publicly rejected a takeover bid by larger rival Amgen and put itself up for sale.
In a complaint filed on Wednesday with the U.S. District Court in Manhattan, the SEC said the "highly suspicious" trades took place between June 26 and 28, and resulted in a profit of about $4.6 million on a $305,000 investment. The SEC said this equated to a return of about 14,200 percent.
An emergency court order freezing the assets of the traders was entered on Wednesday, the SEC said. On June 30, Onyx rejected as inadequate a $10 billion unsolicited takeover bid from Amgen that valued it at $120 per share, 38.2 percent above Onyx's closing price the prior Friday, but said it would consider other potential acquirers. Shares of Onyx soared more than 51 percent on July 1.