Someone, or rather up to 100 someones, apparently knew what was coming. And they placed their bets accordingly.
Susquehanna International Group, one of the largest quantitative trading firms on the planet, filed a lawsuit in Manhattan federal court on June 29 against up to 100 unnamed “John Doe” defendants. The allegation: these traders used inside information about a Chinese government crackdown on cross-border brokerages to load up on short-dated put options, turning roughly $12 million in purchases into profits exceeding $100 million. That’s a return north of 900%.
Susquehanna, which sat on the other side of those trades as a market maker, says it lost over $70 million in the process. The firm is now asking courts to force brokerages to hand over account holder identities and freeze assets while the investigation unfolds.
The trade that was too perfect
In May 2026, Chinese regulators moved to crack down on cross-border brokerage operations. Two companies caught in the crossfire were Futu Holdings (FUTU) and Up Fintech Holdings, better known as Tiger Brokers (TIGR), both of which are US-listed Chinese fintech firms that facilitate international securities trading for Chinese investors. Futu was subsequently hit with a penalty amounting to 1.85 billion yuan due to regulatory violations.
