Insider Trading
Trading (or tipping others to trade) on material, nonpublic information in breach of a duty; both the tipper and the tippee are liable, and penalties reach treble civil damages plus criminal fines and prison.
The Insider Trading and Securities Fraud Enforcement Act of 1988 set the modern penalty structure and rewards whistleblowers. Firms must maintain information barriers (‘Chinese walls’) between investment banking and trading to contain inside information.