Cryptocurrency exchange operator FTX.US has hired former Citadel Securities executive Brett Harrison as its first president.

Harrison will be in charge of helping FTX.US “massively scale out,” FTX.US CEO Sam Bankman-Fried said in a statement Thursday. Harrison’s expertise is in developing trading technology. In his most recent role at Citadel Securities, Harrison was head of semi-systematic technology, where he oversaw a team of more than 100 engineers.

Bankman-Fried highlighted Harrison’s technical skills, along with his business acumen. The duo previously worked together at proprietary trading firm Jane Street for three years.

Growing FTX.US “into the most trusted digital currency trading platform and exchange in the US market” will be Harrison’s primary goal in the new role, said the exchange operator.

FTX.US was launched in May 2020, but its trading volumes have remained tepid compared to the main FTX exchange — which earlier this month hired a former forex sales executive from HSBC. In the last 24 hours, FTX.US handled only about $185 million worth of volume, according to CoinGecko, compared to the nearly $2 billion worth of trading volume facilitated by the main exchange.

Crypto exchanges Binance and Binance.US are in a similar situation. It’s likely one of the reasons why Binance.US recently hired Brian Brooks, the former head of the Office of the Comptroller of the Currency and chief compliance officer of Coinbase, as its CEO.

Both Binance and FTX.US appear to have plans to take on leading U.S. crypto exchanges such as Coinbase and Kraken.