Brett Harrison, president of cryptocurrency exchange FTX US, is stepping down. Harrison will join the company as an advisor in the coming months, he said on Twitter on Tuesday. He did not say who will succeed him as president. Harrison was previously the head of semi-systematic technology at billionaire Ken Griffin’s market maker Citadel Securities and the head of trading systems technology at quantitative trading firm Jane Street. Despite the price volatility, Harrison stated that he would remain in the crypto sector.