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 (311)
- Research
Principal Financial Q1 2026 Preview: A Slight AUM Dip Hid Big Moves in Netflix and Brookfield
Principal’s Q4 2025 filing looked slightly weaker on headline AUM, but the internal rotation was more revealing: Brookfield became a top-ten position, Netflix surged, and the fund cut back in parts of real estate. The next filing will show whether that shift keeps going.
- Research
Nuveen Q1 2026 Preview: A $381.9B Giant Added Credit and Bond ETFs Without Abandoning AI
Nuveen’s Q4 2025 filing stayed large-cap and AI-heavy at the top, but the more revealing addition was a sizable fixed-income sleeve through NXUS and NHYB. The next filing will show whether those credit and bond ETFs remain central or fade back out.
- Research
Janus Henderson Q1 2026 Preview: A $223B Growth Book Added Intuitive Surgical and Biotech Risk
Janus Henderson kept Nvidia and Microsoft on top in Q4 2025, but the more interesting signal was underneath: new exposure to Intuitive Surgical, Protagonist Therapeutics and other growth-healthcare names. The next filing will show whether that rotation keeps building.
- Research
Fisher Asset Management Q1 2026 Preview: Why a $20B Bond ETF Sleeve Now Matters More Than One Stock
Fisher’s Q4 2025 filing was still packed with mega-cap tech, but the bigger tell was a giant Treasury and investment-grade corporate bond sleeve built through IEF and VCIT. The next filing will show whether that duration bet was tactical or structural.
- Research
Dodge & Cox Q1 2026 Preview: Brookfield, TransUnion and PDD Broke a Flat Quarter
Dodge & Cox’s Q4 2025 filing barely moved on headline AUM, but the underlying changes were more interesting: fresh positions in Brookfield, TransUnion and PDD inside a still-diversified value book. The next filing will show whether those adds were conviction moves or just incremental reshuffling.
- Research
CalPERS Q1 2026 Preview: The $174.9B Pension Book Leaned Harder Into VOO and Mega-Cap Tech
CalPERS used Q4 2025 to keep broad-market exposure high through VOO while still adding to Nvidia, Microsoft, Alphabet and Broadcom. The next filing will show whether the pension giant keeps that simple beta-heavy structure or rotates again.
- Research
AQR Q1 2026 Preview: A $190.6B Quant Giant Just Added 69 New Positions
AQR’s Q4 2025 filing kept expanding, with AUM rising to $190.63B, 69 new names, and a dramatic Bristol Myers build inside an already broad book. The next filing will show whether the quant giant keeps pressing this expansion or starts normalizing the roster again.
- Research
American Century Q1 2026 Preview: Netflix, CEG and New Adds Changed the Shape of a $199B Book
American Century’s Q4 2025 filing kept Nvidia and Microsoft on top, but the more revealing changes were the big Netflix increase, fresh utility and industrial additions, and a continued AI-heavy core. The next filing will show whether those side bets keep scaling.
- Research
AllianceBernstein Q1 2026 Preview: Intuitive Surgical and Netflix Rose as the Next Watchlist Names
AllianceBernstein kept Nvidia, Microsoft and Amazon on top in Q4 2025, but new exposure to Intuitive Surgical and aggressive increases in Netflix and ServiceNow made the next filing more interesting than another mega-cap recap. Here is what to watch.
- 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.
- Research
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.
- Research
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.
- Research
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.
- Research
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.
- Research
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.