How do you see which stocks institutions bought last quarter?
Investment managers with at least $100 million in US equities and other covered securities file Form 13F with the SEC within 45 days after each quarter ends, listing what they held on the last day of the quarter (SEC Form 13F FAQ). Comparing two quarters shows which companies gained or lost holders. Tamarly's 13F tracker lists the companies with the largest change in institutional holders, grouped by industry.
What does a change in holders tell you?
A rise in the number of managers holding a company shows that more institutions started a position over the quarter; a fall shows that more left. The tracker counts holders, not shares or value, so a single large manager selling counts once. It is a measure of breadth: how widely a company is held by institutions, and how that moved.
What are the limits of 13F data?
The filing is a snapshot at quarter end and arrives up to 45 days later (SEC Form 13F FAQ), so positions may have changed since. It covers long positions in covered securities only: no short positions, and no holdings of managers below the threshold. Read it as a record of the past quarter, not of today.
Step by step
1. Open the 13F tracker and read "Most added", grouped by industry; each group opens with its largest rise. 2. Read "Most sold" for the other side. 3. Open a company to see who holds it and who changed their position, at its holders page. 4. For how to read the filing itself, see how to read a 13F filing.
Where does Tamarly fit, and where does another tool fit better?
Tamarly fits when you want the quarter's changes by industry, with every holder linked to its filing and to the fund manager's page. The tracker is open to everyone. It does not estimate a manager's returns, show share prices on open pages or follow positions between filings; those need the manager's own reports. Tamarly describes what the filings say and gives no advice to buy, sell or hold.
Open the 13F tracker, free and grouped by industry
Frequently asked questions
Who has to file Form 13F?
Institutional investment managers with investment discretion over at least $100 million in covered securities, mostly US-listed shares (17 CFR 240.13f-1, eCFR).
How current is 13F data?
It shows holdings on the last day of the quarter and is filed up to 45 days later (SEC Form 13F FAQ). The Tamarly tracker updates as the filings arrive.
Does a rise in holders mean a stock will go up?
No. It records what managers held at quarter end. Tamarly gives research, never advice to buy, sell or hold.
About the author. Melvine Manchau is the founder of Tamarly and author of the Tamarly Newsletter. He previously worked at PwC, Salesforce, BlackRock/eFront and Lazard.
About Tamarly Research. Tamarly Research is part of Tamarly Media, which holds no investment positions. Tamarly is a New York research house that studies how AI is changing regulated institutions.