Ebay stock options have become increasingly active in the past three months, as a series of very large bullish bets indicate substantial hedge fund interest in the stock.
Over the course of four major options trades, 159,000 calls were bought, for a total outlay of nearly $18 million in premium. And as traders—or one big trader—snatched up the calls, open interest in the stock options skyrocketed.
Many of the trades appeared to target eBay's January earnings announcement. The company did end up reporting a strong fourth quarter, but that news was overshadowed by the revelation that Carl Icahn had taken a stake in the company and planned to use activism to spur change.
Despite that, the stock has lost ground from its trading level before those announcements.
(Read more: EBay dismisses Icahn proposal to spin off PayPal)
"The options activity equated to buying a rumor, and the action after the news was a classic 'sell the news,' " Nathan said.