Check out the companies making headlines after the bell Monday:
A. Schulman - The plastics provider's stock tumbled some 3 percent in extended trading after it reported adjusted fiscal second-quarter earnings of 39 cents per share on $542.3 million in sales.
Viacom - The media company's shares edged lower after it said it would reorganize three domestic network groups in an effort to spur growth. It will take a $785 million pre-tax charge in relation to the deal.
Clovis Oncology - The biopharmaceutical maker's stock rose about 7 percent after it said the FDA had granted breakthrough therapy designation for a rucaparib treatment for ovarian cancer.
Dyax - Shares fell about 4 percent after the drugmaker proposed a public offering of 7 million shares of common stock.
New Residential - The real estate investment trust said it reached a multi-year extension of service contracts with Ocwen. New Residential shares fell 5 percent, while Ocwen rallied about 9 percent.
Six Flags - The theme park operator's stock increased about 2 percent after it formally announced that it would release its fiscal first-quarter results on April 22, 2015.