(Reuters) - Robinhood Markets Inc fell more than 10% in premarket trading on Thursday after a four-day surge during which its market value doubled as retail traders piled into the online brokerage's stock.

It was the third most-traded stock across U.S. exchanges before the opening bell and was down at $63.05. After a tepid debut last week, the stock rose more than 50% in the previous session and soared to as much as $85, before closing at $70.39 to notch a market capitalization of $58.8 billion.

"Retail traders are perhaps more level-headed than their reputation for 'buy and hold no matter what' might indicate," said Nicholas Colas, co-founder of DataTrek Research.

The stock has surged way past its initial public offering price of $38. Volumes have also shot up, with more than 175 million shares traded on Wednesday, the first day that investors could trade options on Robinhood shares.

Robinhood was the third most bought stock on retail platforms on Wednesday, according to Vanda Research.

The company said on Thursday its stockholders could sell up to 97.9 million of shares and that the company will not receive any of the proceeds, according to a regulatory filing.

(Reporting by Sruthi Shankar and Medha Singh in Bengaluru; Editing by Arun Koyyur)