Citadel Securities Joins Susquehanna’s Insider Trading Lawsuit Over Alleged $137M Scheme

Two rival options market makers say anonymous traders profited from advance knowledge of China's action against Futu and Tiger Brokers.

Susquehanna filed its complaint in the Southern District of New York on June 29. Citadel Securities moved to intervene three days later. Susquehanna estimates its losses at about $70 million; Citadel puts its own at roughly $28 million.

Both firms allege they sold thousands of short-dated put options to traders acting on material non-public information, generating profits of at least $137 million.

Citadel Securities said it was the victim of the same alleged insider-trading scheme that rival Susquehanna claims made more than $100 million on options bets ahead of a Chinese regulatory crackdown https://t.co/Z4mvpJPJ2d

— Bloomberg (@business) July 6, 2026

The Trades Preceded China's Move Against Futu and Tiger

The options were tied to US-listed Chinese brokerages Futu Holdings and UP Fintech, known as Tiger Brokers. On May 22, the China Securities Regulatory Commission announced plans to penalise Futu, Tiger and Longbridge Securities for operating on the mainland without a licence, including confiscation of "illegal gains" from their domestic and overseas entities.

The firms have been granted a formal hearing before penalties are finalised. Tiger's ADRs fell as much as 47% in premarket trading that day, while Futu dropped 35%. Both complaints allege the put purchases in the days before the announcement drew on non-public knowledge of the impending action.

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Why Citadel Moved to Intervene

On the day Susquehanna filed, the court granted a temporary restraining order freezing the defendants' proceeds and authorised expedited discovery.

According to Bloomberg, the discovery targets client records held at Interactive Brokers, Futu and TradeUp Securities; Interactive Brokers told Bloomberg it is cooperating, including freezing accounts.

Citadel's memorandum states the reason for intervening plainly: the frozen funds are a potentially finite pool, and any recovery by Susquehanna could reduce what remains available to Citadel Securities.

Susquehanna does not oppose the motion. Both firms rely on Section 20A of the Exchange Act, which gives a private right of action to investors who traded contemporaneously with an insider.

What Comes Next

A preliminary injunction hearing is scheduled for July 10, with Citadel Securities intending to participate if its motion is granted. The next phase of the case will determine whether expedited discovery turns the John Doe defendants into named individuals.