Online brokerage platform Robinhood, which has popularised free stock trades and drawn scrutiny from regulators, has filed confidentially for an initial public offering (IPO), media reports said on March 23.

Axios and Bloomberg News cited people familiar with the matter, noting that Robinhood had taken advantage of a regulation allowing for the IPO filing without immediate disclosure of its finances.

Robinhood, which has sought to bring stock trades to a broader audience, has been at the centre of a controversy after it was used to pump up the prices of beaten-down stocks like GameStop, which has seen extreme volatility in its share price.

Its co-founder and CEO Vlad Tenev was among executives called to testify at a recent congressional hearing on retail investing.

Tenev denied that the trading app was part of any effort to manipulate stock prices.

He told lawmakers: “All I can say is Robinhood played it by the books.”

Details of the IPO were not immediately known but Bloomberg said the listing would be on the Nasdaq exchange.

Some reports said Robinhood’s market valuation could be as high as $40 billion.

The app popular among retail investors has a stated goal to “democratise finance for all”, allowing free stock trades even for small amounts.

On the New York Stock Exchange, GameStop’s share price fell $12.74 or 6.55 per cent to close at $181.75 on March 23 for a market capitalisation of $12.71 billion, with 14.43 million shares traded.