Robinhood shares surged as much as 82 per cent at the start of trading on Wednesday, prompting multiple trading halts as the market capitalisation of the newly listed US brokerage briefly climbed to $71bn.

The rally, which lifted the stock to a high of $85, has accompanied a furious start to trading in the company’s stock. Before 10am more than 30m Robinhood shares had changed hands, making it the most heavily traded stock among large and midsized companies, according to Bloomberg data.

The company had a rocky debut after its initial public offering last week. Shares of the Nasdaq-listed company fell 8.4 per cent on its first day of trading, one of the worst performances for a flotation of its size. Some large asset managers had decided not to invest in the IPO as they worried about regulatory risks to the company’s business.

Traders and investors had also girded themselves for volatile trading in Robinhood stock, given the company had allotted a large portion of its shares to retail traders on its own platform, an unusual move in a listing.

The gain on Wednesday pushed Robinhood’s market valuation ahead of hundreds of blue-chip US companies, including carmaker Ford, foods behemoth Kraft Heinz and asset manager T Rowe Price.