The stock rose as much as 4.7 percent in unusually heavy volume in the morning, with two European-based traders and one U.S.-based trader citing rumours that Google would possibly take a large stake in eBay as the reason for the move.

"We’ve had no conversations with Google about acquiring a stake in the company," eBay spokesman Alan Marks said.

Google said it would not comment on rumours or speculation.

EBay shares were up 2.6 percent at $52.02 at midday after rising as high as $53.07. Google dipped 0.7 percent to $587.08.

Options volume in eBay spiked to 2.4 times normal, with 98,000 puts and 26,000 calls traded late into the morning session, according to data from options analytics firm Trade Alert.

(Reporting by Rodrigo Campos, Saqib Iqbal Ahmed and Alexei Oreskovic; Editing by Jeffrey Benkoe)