Form 4 Insider Trading Patterns

Form 4 filings disclose every insider transaction within 2 business days. Most retail analysis stops at 'CEO sold X shares.' The interesting work is in cluster behavior — when 3+ insiders at the same company sell within a 10-day window — and in director interlocks, where a director sitting on multiple boards sells at one company before trouble appears at the others.

This project builds a backtested insider cluster signal with out-of-sample validation, tracks 10b5-1 plan adoption timing relative to earnings, and maps the director interlock network.

Data source: SEC EDGAR Form 4 XML filings (~500K/year). Price data via yfinance.