The SEC is examining Susquehanna International Group's claims that anonymous traders profited roughly $100 million from options positions placed before Chinese regulators targeted cross-border brokerages. Susquehanna alleges these trades exploited advance knowledge of Beijing's crackdown on offshore securities trading platforms.

Susquehanna Investment Group filed suit against 100 unnamed defendants, saying they bought options that surged in value when shares of three Nasdaq-listed brokers plunged after the Chinese financial regulator's announcement. The firm lost approximately $70 million from being on the opposite side of these trades. Most transactions flowed through Interactive Brokers, according to court filings.

Susquehanna argues the alleged illegal profits exceed those from the infamous Galleon case that imprisoned Raj Rajaratnam in the early 2010s. This highlights how traditional markets remain vulnerable to insider trading despite the rise of prediction platforms like Kalshi and Polymarket.

The investigation underscores ongoing regulatory scrutiny of cross-border trading flows and the persistent challenge of detecting market manipulation. For investors, it signals that even sophisticated trading firms can fall victim to information asymmetries in our interconnected global markets.