SeaWorld, Mattress Firm Lead Thursday's After-Hours Movers By: Benzinga via Benzinga March 19, 2015 at 17:49 PM EDT Prothena Corporation PLC (NASDAQ: PRTA) jumped 37 percent to $40.16 in the extended session Thursday on news that the company's ... Read More >> Related Stocks: Magnachip Semiconductor Corp New York & Company Prothena Corp Seaworld Entertainment Inc Company Vascular Biogen. Ord Vectrus Inc