Marcus Chen
Senior Market Analyst
Senior Market Analyst at 13F Insight. Covers institutional portfolio strategy, 13F filings, and smart money trends.
A note from Marcus
Hi, I'm Marcus. I spent six years on the buy side staring at 13F filings for a hedge fund, and the thing that bothered me most wasn't the work — it was knowing that the average investor never gets to see what I was looking at, even though it's all public.
That's why I'm here. Every research piece you'll see under my name comes from real SEC data, run through real institutional logic, and translated into something you can actually act on. I write long when the data deserves it and short when it doesn't.
If you ever spot a number that looks off, email me. I'd rather be corrected than wrong.
Articles by Marcus Chen (542)
- Research
Berkshire Hathaway Q1 2026 Watchlist: After Verisign and Liberty Adds, What Does Buffett Do Next?
Berkshire ended Q4 2025 with a $274.16B U.S. equity portfolio, steady Apple and American Express stakes, and a fresh set of Verisign, Liberty and New York Times positions. The next filing will show whether those adds were the start of a new sleeve or just tactical cleanup.
- Research
Druckenmiller Q1 2026 Watchlist: After a $914M ETF Blitz, What Could Duquesne Do Next?
Stanley Druckenmiller's Q4 2025 filing added XLF, EWZ and RSP in size while keeping Natera on top. Ahead of the May 15, 2026 deadline, the question is whether that macro overlay expands or fades.
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Coatue Q1 2026 Preview: A $39.96B Tech Fund Just Rebuilt Around TSM, Microsoft and a CRWV Exit
Coatue's Q4 2025 13F shows fresh top positions in TSM, Microsoft, Amazon, LRCX and AMAT, plus a notable CoreWeave exit. Q1 2026 will reveal whether that AI infrastructure rebuild sticks.
- Research
Wellington Management's Q4 2025 13F Shows What Platform-Scale Diversification Looks Like
Wellington Management ended Q4 2025 with $570.66 billion in reported 13F AUM, 7,580 positions, and a top-10 basket worth just 29.5% of the portfolio. The filing highlights how a private, independent asset manager translates platform breadth into a remarkably balanced public-equity book.
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Dodge & Cox Q4 2025 Portfolio: A $185.26B Value Giant Still Hunting Outside Mega-Cap Momentum
Dodge & Cox ended Q4 2025 with $185.26B in 13F assets, 222 holdings, and a top book led by Charles Schwab, Johnson Controls, RTX, CVS Health, and FedEx.
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Legal & General Q4 2025: $450.91B insurer leans on U.S. mega-caps
Legal & General ended 2025Q4 with $450.91B in reported 13F AUM, a 71.75 WhaleScore, and a top U.S. equity book led by NVDA, AAPL, and MSFT.
- Learn
The 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.
- Learn
What 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.
- Learn
How 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.
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Swiss National Bank's $168.01B US Equity Book Shows How a Central Bank Buys America's Mega-Caps
Swiss National Bank reported a $168.01B 13F portfolio for Q4 2025. The filing shows how a reserve manager gets US equity exposure: passive, diversified, and overwhelmingly tilted toward mega-cap technology.
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Berkshire Hathaway Q4 2025: Buffett’s $274.16B portfolio posts the highest WhaleScore in the market
Berkshire Hathaway closed 2025Q4 with $274.16B in reported 13F assets, 110 disclosed holdings, and an 85.75 WhaleScore that led all filers. The quarter reads like a high-conviction Buffett snapshot just as Greg Abel steps into the CEO role.
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Bridgewater Q1 2026 Preview: After a $2.87B IVV Bet and a +102% QoQ Jump, What Does the Macro Giant Do Next?
Bridgewater ended Q4 2025 with $27.42B in visible 13F AUM, 1,040 holdings, and a surprisingly index-heavy core led by SPY and IVV. Q1 2026 will show whether that reset was tactical or durable.
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Norges Bank Q4 2025: Why a $935B Sovereign Fund Still Stopped at 1,577 Positions
Norges Bank's Q4 2025 13F disclosed $934.76B across just 1,577 positions, showing why sovereign-scale capital can still look highly selective in U.S. equities.
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Norges Bank's $62.24B NVIDIA Stake Anchors a $934.76B U.S. Portfolio
Norway's sovereign wealth fund disclosed a $934.76B U.S. equity portfolio in Q4 2025, led by a $62.24B NVIDIA stake and a tightly curated mega-cap core.
- Research
Norges Bank Q4 2025: $935B Sovereign Fund Holds Just 1,577 Positions
Norway Government Pension Fund Global reported $934.76 billion in US equities across just 1,577 positions in Q4 2025. Here is how the world largest sovereign wealth fund selects its US holdings.
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Dimensional Fund Advisors Q4 2025: Academic factor investing at $476.72B scale
Dimensional Fund Advisors ended 2025 with $476.72B of reported 13F AUM and 13,709 holdings, showing how a Fama-French-style factor process still works at immense scale.
- Learn
What Quarterly AUM Jumps Really Mean: Normal Market Moves vs. New Money vs. Filing Changes
A 10% quarterly AUM move is usually market drift. A 50% move may be new money, a filing-entity reset, or a reporting-basis change. Here is the decision tree investors should use before overreacting to a 13F jump.
- Research
Geode Capital Management’s $1.62T Q4 2025 Filing Reveals Fidelity’s Shadow Index Giant
Geode Capital Management’s Q4 2025 13F highlights how a behind-the-scenes Fidelity sub-adviser concentrated enormous benchmark-driven capital in Nvidia, Apple, Microsoft, and other mega-cap leaders.
- Research
Fairholme Capital Q4 2025: Bruce Berkowitz's 80% Conviction in St. Joe Company
Fairholme Capital Management's $1.43B portfolio reveals extreme conviction, with real estate developer St. Joe Company (JOE) commanding over 80% of assets.
- Research
Scion Asset Q4 2025: Michael Burry's Astonishing 80% Bet on Palantir
Michael Burry's Scion Asset Management revealed a highly concentrated 4-stock portfolio in Q4 2025, with Palantir making up over 80% of the assets.