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 (326)
- Learn
The Hidden Risks of Following Institutional Trades: Lag, Liquidity, and Position Sizing
A famous fund name on a 13F can be useful, but copying the trade blindly is where retail investors get into trouble. Here is how delay, liquidity, and sizing distort the signal.
- Research
Why Loomis Sayles’ Q4 2025 13F Jumped From $84.1M to $82.47B
Loomis Sayles, long associated with fixed income and the Dan Fuss legacy, suddenly reported $82.47B in Q4 2025 13F assets after showing just $84.1M in Q3. The filing looks less like an overnight risk binge and more like a reporting-footprint reset.
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What Did Rajiv Jain Own in Q4 2025? GQG’s $60.72B 13F Put 51.3% in Its Top 10
GQG Partners reported $60.72B in Q4 2025 13F AUM across just 87 positions, with 51.3% of the portfolio concentrated in its top 10 holdings — a classic Rajiv Jain conviction profile.
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Pictet's $103.05B Q4 2025 U.S. Book Barely Budged. That's What Makes It Interesting.
Pictet Asset Management Holding SA kept its Q4 2025 13F book near record highs while refining, rather than abandoning, a quality-growth and healthcare-heavy portfolio.
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Manulife's $121.70B 13F Stayed Flat, but Q4 2025 Looks More Selective
Manufacturers Life Insurance Company, The finished 2025Q4 with $121.70B in reported 13F AUM and a holdings count that fell to 2,850 even as Microsoft, Nvidia, and Amazon led the visible equity book.
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Sector Rotation vs. Index Buying: Reading the Macro Tea Leaves in 13F Filings
When mega-filers load up on SPY or QQQ, are they hedging, or just parking cash? Here's how to distinguish macro positioning from genuine conviction.
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Mastering the Insider Cluster Signal: How to Spot Multiple Executives Buying at the Same Time
A single insider buy is interesting, but an 'insider cluster' is powerful. Learn how to identify when multiple executives are buying at once.
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Why Institutional Selling Doesn't Always Mean a Bearish Thesis: Rebalancing vs. Conviction Shifts
Don't panic when you see a fund trimming its top holdings. Learn how to distinguish between tactical rebalancing and a real shift in investment thesis.
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Decoding 13F vs. 13D Filings: Why One Is a Quarterly Snapshot and the Other is a Red Alert
Learn the critical differences between delayed 13F reports and the rapid-fire 13D filings that signal active institutional moves.
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How to Read Position Rank Changes Without Overreacting to Market Moves
A stocks rank in a portfolio can jump even when the manager barely touched the shares. Here is how to read rank changes without turning market movement into a false signal.
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How to Use Stock Holder Pages to See If a Trade Is Crowded
Before you chase a popular idea, check the stock holder page. It is the fastest way to see whether a trade is truly crowded or just widely known.
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How to Read Mega-Cap Overlap Without Assuming Funds Are Copying Each Other
Lots of filers own the same mega-cap names. That does not mean they share the same thesis. Here is how to tell real consensus from shallow overlap.
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How to Use Insider Profiles With 13F Data to Build Event-Driven Watchlists
The best watchlists combine institutional ownership with insider behavior. Here is a practical workflow using insider profiles, stock pages, and filer pages together.
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When 13F AUM and Holdings Value Do Not Match: A Simple Sanity Check
Sometimes the headline 13F AUM and the visible holdings sum tell different stories. Here is how to sanity-check the numbers before you repeat the wrong one.
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How to Read ETF Positions in a 13F Without Mistaking Them for Stock Picks
ETF-heavy filings can look active when they are really just broad exposure sleeves. Here is how to spot the difference before you copy the wrong signal.
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How to Use Historical Quarter Pages to Find Real Position Changes
Historical quarter pages are the easiest way to stop comparing the wrong snapshots. Here is how to use them to isolate real change instead of filing-noise.
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How to Compare Two 13F Filers Without Letting AUM Fool You
A bigger 13F portfolio does not automatically mean a better idea source. Here is a cleaner way to compare managers using concentration, turnover, and stock-level context.
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How to Track What Buffett Bought in Q4 2025 Using 13F Filings
Buffett's Berkshire Hathaway holds $274B across 42 positions. Here's how to read his Q4 2025 13F — what he added, what he trimmed, and how to follow his next move before most investors notice.
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How to Sanity-Check a 13F Thesis in 10 Minutes
Before copying a trade idea from institutional filings, run this 10-minute sanity-check workflow using filer quality, concentration context, and stock-level holder data.
- Learn
13F Value vs Shares: Why You Need Both to Read Institutional Conviction
A position's dollar value can rise even when a manager trims shares. Learn how to use both value and share count to avoid false conclusions in 13F analysis.