Sarah Mitchell
Education Editor
Investment Education Editor at 13F Insight. Breaks down complex institutional data into actionable insights for individual investors.
A note from Sarah
Hi, I'm Sarah. I spent four years at Vanguard's Investor Education team, where my whole job was making 401(k) statements feel less like tax forms and more like something a person could actually understand.
I'm here at 13F Insight to do the same thing for institutional data. If you've ever read a headline like "Berkshire Bought Apple" and thought "okay but what does that actually mean for me," that's the gap I want to close.
I'll never assume you know what a CUSIP is. I'll always tell you why a number matters before I give you the number. And if a guide of mine ever leaves you more confused than you started, that's on me — let me know and I'll rewrite it.
Articles by Sarah Mitchell (818)
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How 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.
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How 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.
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Why 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.
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Understanding 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.
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How 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.
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How 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.
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How 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
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How 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
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Why 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.
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Index 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.
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How 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.
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How 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.
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How to Read Form 4 Insider Filings Before 13F Season: The Codes That Actually Matter
Form 4 filings usually arrive within two business days of a trade, which makes them much faster than 13Fs. Here is how to read the key transaction codes, separate sales from awards, and use insider data without overreacting.
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Q1 2026 13F Filing Dates: Exact SEC Deadlines and What Comes Out When
The SEC's current Form 13F FAQ lists Friday, May 15, 2026 as the Q1 2026 filing deadline. Here is the full date map, what investors should expect to arrive first, and how to track filings without refreshing EDGAR all day.
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Tiger Global Q1 2026 Preview: Microsoft, Amazon and TSM Crashed Into the Top 10. Is the Re-Risking Real?
Tiger Global's Q4 2025 13F shows a $29.71B book, 54 holdings, and a new top layer shaped by Microsoft, Amazon, TSM, and Take-Two. Q1 2026 will show whether the rebuild is real or still provisional.
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Barclays Q4 2025: Why a $73B SPY Position Anchors This $417B Bank 13F
Barclays PLC reported $416.70 billion in Q4 2025 with 18.75% in a single SPY position. Here is why the British bank's 13F looks different from traditional asset managers and what it reveals about structured products hedging.
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Nuveen Q4 2025: How TIAA Invests $382B of America's Educator Retirement Savings
Nuveen, TIAA's investment arm, reported $381.90 billion in Q4 2025 13F value. Here is how the retirement manager for millions of educators and nonprofit workers positions their equity portfolio.
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Franklin Templeton Q4 2025: Why a $19.33B Microsoft stake sits atop a $407.59B 13F portfolio
Franklin Resources closed 2025Q4 with $407.59B in reported 13F assets, 14,263 disclosed holdings, and a 65.25 WhaleScore. Sarah Mitchell breaks down why Microsoft leads the book, what the top positions say about Franklin Templeton’s U.S. equity exposure, and how to read the filing against the firm’s broader business story.
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Understanding 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.
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Why 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.