Smart Money / 13F
45-day lag, survivorship bias, and when copying actually works
Once a quarter, every institutional manager with $100M+ under management has to tell the SEC what they own. Those filings are public. Copying the smartest investors should be easy — except for the lag, the omissions, and the survivorship bias built into who you decide to follow.
A 13F filing is a quarterly snapshot of an institutional manager's long U.S. equity book.
It tells you what they OWNED on the last day of the quarter. It does not tell you when they bought, what they paid, what they short, what they hedge with, or what they sold during the quarter. Filings are due 45 calendar days after quarter end.
By the time you see Berkshire's Q1 holdings, it's mid-May — anywhere from 45 to 135 days after individual trades happened. The most-discussed positions have already moved. The signal is real but stale; treat 13F as a STARTING POINT for research, not as a real-time copy-trade source.
That is the opening. Finishing a lesson is where it stops being interesting and starts being useful: the full lesson runs to 7 sections and ends with 3 practice questions. A free account is what opens the rest, and the other 255 lessons in the Academy with it. No card.
What this lesson covers
- 1The 45-Day Lag
- 2What 13F Doesn't Show
- 3Survivorship Bias
- 413F Filing Mechanics
- 5Cohen, Frazzini & Malloy 2010 — When Copying Works
- 6What this looks like on the Institutional / Superinvestors tab
- 7Summary