Updated Apr 24, 2026 · 798 articles
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Educational guides about 13F filings, insider trading, institutional investing, and how to track smart money moves.
How to Use 13D and 13G Filing Clusters With 13F Holder Data
A 13D or 13G filing becomes more useful when you read it next to the institutional holder base. This guide explains how to combine threshold filings with 13F data without overreacting.
Sarah MitchellHow to Read a Diversified 13F Portfolio When the Top 10 Stays Under 30%
Many institutional portfolios look boring because no single position dominates. This guide explains how to read diversified 13F books without mistaking breadth for lack of conviction.
Sarah MitchellHow to Use Holder Count Without Confusing Popularity With Conviction
Holder count is useful, but it does not tell you conviction by itself. Here is how to pair breadth with holder mix and concentration.
Sarah MitchellWhy Mega-Cap Top Holder Lists Look Passive and What to Do Next
Mega-cap stock pages often look passive at the top. Here is how to find the real ownership signal underneath the index layer.
Sarah MitchellUnderstanding AUM in 13F Filings: What the Big Number Really Means
AUM is useful context, but it is not the same thing as conviction. Here is how to read 13F AUM without overstating what a portfolio really says.
Sarah MitchellHow to Read 13D and 13G Amendments Without Overstating Activism
Not every 13D or 13G amendment is a new campaign. Here is how to tell a real control signal from routine ownership maintenance.
Sarah MitchellHow to Read 13F Sector Research Without Overstating Coverage
Sector articles are useful only if you remember they describe a covered stock set, not an entire market. Here is how to read them without overstating what the data proves.
Sarah MitchellHow to Separate 13F Price Effects From Real Position Changes
The Most Common 13F Mistake A 13F position can look bigger because the manager bought more shares, because the stock price rose, or because both happened. It can also look smaller even when the share count increased if
Sarah MitchellHow to Read Mega-Filer 13Fs Without Blindly Cloning Them
Why Mega-Filer 13Fs Need a Different Lens A 13F from a hedge fund, a family office, a bank, and an index manager can all show the same stock table, but the meaning is not the same. A concentrated hedge fund position ma
Sarah MitchellWhy Form 4 Table I and Table II Can Tell Two Different Ownership Stories
A Form 4 can show direct Class A sales in Table I while Table II still reveals millions of derivative or indirect shares. Here is how to read both tables without making a false “owns zero shares” claim.
Sarah MitchellIndex Allocator or Stock Picker? How to Tell What a 13F Manager Really Is
Some 13F filers are better read as asset allocators, while others are better read as concentrated stock pickers. Here is how to tell the difference quickly and why the distinction matters.
Sarah MitchellHow to Build a 13F Watchlist Before the Next Filing Deadline
The best 13F research starts before the filing arrives. Here is how to use the last quarter’s holdings, concentration, new positions and ETF sleeves to build a smarter watchlist ahead of the next deadline.
Sarah MitchellHow ETF and Bond Sleeves Change the Way You Read 13F Conviction Signals
A portfolio packed with ETFs and bond funds should not be read the same way as a concentrated stock-picking book. Here is how ETF sleeves change position-level meaning inside a 13F.
Sarah MitchellThe Family Office Blind Spot in 13F Data: What You Cannot See
Family offices managing trillions globally are largely invisible in 13F filings. Here is why they are exempt, how big the blind spot is, and how to partially fill the gap using other SEC filings.
Marcus ChenUnderstanding 13F Amendment Filings: HR vs HR/A Explained
Not every 13F is the final word. Amendments (13F-HR/A) can restate holdings, reveal hidden positions, and change portfolio data retroactively. Here is how to handle them.
Sarah MitchellWhat WhaleScore Means and How to Use It on 13F Insight
WhaleScore is a portfolio quality heuristic on 13F Insight that ranges from 0 to 100. Here is what it measures, how to interpret it, and how to use it for smarter institutional research.
Marcus ChenHow to Compare Institutional Portfolios Using Concentration Metrics
Not all 13F portfolios carry equal signal. Here is how Top-5 concentration and position count help distinguish conviction stock pickers from index trackers.
Marcus ChenWhy 13F Data Is Always 45 Days Old: The Filing Delay Explained
Every 13F filing describes positions from at least 45 days ago. Here is why the delay exists and how to use institutional holdings data correctly.
Sarah Mitchell