Susquehanna Investment Group has filed suit against 100 unnamed defendants in Manhattan federal court, accusing them of executing trades based on confidential information about Chinese government restrictions on cross-border brokerages. The Pennsylvania market-maker claims it suffered losses exceeding $70 million as the counterparty on most of the suspicious transactions.

The alleged scheme involved trading activity tied to China's crackdown on brokerage operations, with Susquehanna estimating the illicit trading generated at least $100 million in profits. The firm is pursuing legal remedies to recover its losses and identify the traders behind the transactions, which it describes as among the largest insider-trading cases in recent years.

Federal prosecutors have been investigating the matter, and Susquehanna's lawsuit signals the firm's attempt to recoup damages while regulators pursue criminal charges. The case highlights ongoing concerns about cross-border information flow and market manipulation in volatile geopolitical conditions.

Susquehanna's aggressive legal response reflects how sophisticated trading firms protect themselves against suspected insider trading, particularly when government policy shifts create sudden market-moving opportunities.