Lawyers for Archegos Capital Management founder Bill Hwang are set to ask a federal judge on 21 March to throw out charges tied to the meltdown of the investment firm, saying federal prosecutors have mischaracterised legal trading as criminal market manipulation.

Archegos collapsed during a volatile stretch in the market in March 2021, leading to billions of dollars in losses for banks and investors. Federal prosecutors said Hwang built up big, concentrated positions in companies using swaps — derivative contracts struck with banks for a fee — that allowed him to inflate the prices of stocks in his portfolio and hide Archegos’s market power.