NEW YORK (BLOOMBERG) - Crypto exchange FTX US is expanding its no-fee stock trading service to all US users, including non-crypto investors, in a move to expand its customer base and increase assets under custody.

"Our beta users were from a pool of existing FTX US crypto users," Mr Brett Harrison, president of FTX US, said in an interview. "It will be very interesting when we open it to all to see how many FTX US users start to trade stocks, and to what extent we will be able to bring new users."

The company also plans to add options trading, he said, although no specific timeline was provided.

Last week, Robinhood Markets launched options trading in cash accounts for eligible customers, calling it one of the most requested features from advanced users.

The competition between retail-focused stock trading platforms has heated up, even as the pandemic-driven meme stock movement waned and broader markets cooled. Stocktwits, a social media platform, also entered equities trading this month.

"If we can perfect this product during this period of slow trading volume for retail, if and when the volume picks up again, we would be able to capitalise that opportunity," Mr Harrison said. As part of the full launch, users will now be able to trade stocks on the mobile app.

A key difference for FTX US' equity trading offering is it does not accept payment-for-order-flow, a controversial process in which wholesale firms pay for the right to execute orders coming from the brokerage's retail investors. The practice has become a focus for the United States Securities and Exchange Commission and other critics.

Mr Harrison declined to comment when asked about a potential partnership between FTX and Robinhood. FTX co-founder Sam Bankman-Fried, who has disclosed a 7.6 per cent stake in Robinhood, earlier said he is "excited about Robinhood's business prospects and potential ways we could partner" with it.