Someone knew what was coming. That’s the core allegation from Susquehanna International Group, one of the largest trading firms in the world, which claims a group of mystery traders used inside information about a Chinese regulatory crackdown to make over $100 million in profit. Susquehanna, left holding the bag as a market maker on the other side of those trades, says it lost more than $70 million.
Now the Justice Department and the SEC are both taking a hard look at what happened.
The setup and the sting
Here’s the story in plain English. On May 22, 2026, Chinese authorities announced a crackdown on cross-border brokerage services. The move hammered US-listed shares of Chinese brokerages Futu Holdings and UP Fintech, better known as Tiger Brokers.
But in the days leading up to that announcement, someone went on a shopping spree for short-dated put options on both stocks. Put options are essentially bets that a stock’s price will fall, and short-dated ones are particularly aggressive wagers, cheap if you’re wrong, wildly profitable if you’re right.
