13F Filing

A 13F filing is a quarterly report required by the U.S. Securities and Exchange Commission (SEC) from institutional investment managers who manage at least $100 million in qualifying assets. The filing discloses the manager's equity holdings — including stocks, ETFs, and some options — but does not reveal short positions, cash, bonds, or foreign-only securities.

The filing is due 45 days after the end of each quarter, meaning Q4 data (December 31) is reported by mid-February. This delay is important: by the time the data is public, the manager may have already changed positions significantly.

Example: Warren Buffett's Berkshire Hathaway files a 13F every quarter. His Q4 2025 filing revealed he trimmed Apple and increased his energy holdings — moves that were already 6 weeks old by the time retail investors could see them.

At BMInsider, the Smart Money Tracker uses 13F filings to analyze the portfolios of 15 legendary investors including Warren Buffett, Michael Burry, and Ray Dalio, so you can see what the biggest names in finance are actually buying and selling.