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
Concentrated vs. Broad Whale Books: How Five Giant Filers Approached Q4 2025
A five-filer comparison shows why Berkshire looked like a conviction allocator while the giant diversified managers kept much broader top books in 2025Q4.
- Research
Partners Value Investments Ran a 2025Q4 Filing That Was 92.9% Brookfield
Partners Value Investments L.P. reported a $10.70B book for 2025Q4 with BN and BAM absorbing nearly all of the economic weight. It is a useful example of how a corporate-family filing can still deliver a very strong concentration signal.
- Research
H&H International Rebuilt a 2025Q4 Book Around a 50.3% Apple Weight
H&H International Investment, LLC ended 2025Q4 with $17.49B in 13F assets, and Apple alone represented 50.3% of the filing. The top five names took 89.5% of weight, making the quarter one of the sharper concentrated rebounds in the whale-score cohort.
- Research
Saudi Arabia's Public Investment Fund Cut Down to a Two-Name Core in 2025Q4
Public Investment Fund's 2025Q4 filing shrank to five positions and concentrated 85.2% of assets in Uber and Electronic Arts. That makes the quarter more useful as a conviction map than as a broad market survey.
- Research
Newlands Ran a 17-Stock Growth Book in Q4, With Meta Still at 33.3%
Newlands Management Operations LLC ended 2025Q4 with $19.40B in 13F assets and a very narrow growth stack led by Meta, Robinhood, and Alphabet. The top five names consumed 74.4% of the portfolio, leaving almost no room for filler positions.
- Research
Brookfield Built a 2025Q4 Filing Where BAM Alone Took 77.4% of Weight
Brookfield Corp /ON/ reported an $80.76B 13F book for 2025Q4, and Brookfield Asset Management dominated the filing at 77.4% of weight. The remaining positions matter, but they read more like supporting pieces than co-equal bets.
- Research
Lilly Endowment Kept 100% of Its 13F Book in Eli Lilly in 2026Q1
Lilly Endowment reported an $84.52B 13F portfolio for 2026Q1, and every dollar of it still sat in Eli Lilly. The filing is unusually simple, which is exactly why it makes such a strong case study in institutional concentration.
- Research
70 New Positions At Wellington, 41 At Capital World: The Q4 2025 Whale Rotation Scoreboard
The most useful 2025Q4 question was not just who owned the biggest stocks. It was which large managers rotated the hardest beneath the surface. This scoreboard compares four major 13F portfolios side by side.
- Research
Four Whale Funds Put More Than $138B Into Broadcom In Q4 2025
Broadcom remained the clearest single-stock anchor across several major 13F portfolios in 2025Q4. The weight, not just the dollar total, explains why AVGO kept showing up at the top of institutional books.
- Research
Three Whale Funds Held More Than $14B Of Netflix After Aggressive Q4 2025 Adds
Capital World Investors, Capital Research Global Investors, and Wellington all expanded Netflix exposure in 2025Q4. The combined value reached more than $14B, but the intensity of the adds differed sharply.
- Research
Four Whale Funds Put Nearly $493B Into The AI Mega-Cap Five In Q4 2025
Across four major 13F managers, Apple, Microsoft, Nvidia, Broadcom, and Amazon absorbed nearly $493B of disclosed capital in 2025Q4. The basket was broad, but it was not evenly distributed.
- Research
Ameriprise Q1 2025 Historical Ownership Review: The Diversified Base Before Later Growth Acceleration
AMERIPRISE FINANCIAL INC in 2025Q1 offers a cleaner historical baseline for understanding how the portfolio was positioned before later 2025 shifts became louder.
- Research
Invesco Q1 2025 Historical Ownership Review: The Broad Book Before Later Tesla and Meta Reinforcement
Invesco Ltd. in 2025Q1 offers a cleaner historical baseline for understanding how the portfolio was positioned before later 2025 shifts became louder.
- Research
Wellington Management Q2 2025 Historical Ownership Review: The Pre-Rotation Snapshot Before Later Defensive Adds
WELLINGTON MANAGEMENT GROUP LLP's 2025Q2 filing provides a clean baseline for understanding how the portfolio was positioned before later 2025 quarter-end changes took more of the attention.
- Research
Capital World Investors Q2 2025 Historical Ownership Review: The Broad Core Before Later Edge Rotation
Capital World Investors's 2025Q2 filing provides a clean baseline for understanding how the portfolio was positioned before later 2025 quarter-end changes took more of the attention.
- Research
ALLIANCEBERNSTEIN L.P. Q2 2025 Historical Ownership Review: What the Growth Book Looked Like Before Later AI Trims
ALLIANCEBERNSTEIN L.P.'s 2025Q2 filing provides a clean baseline for understanding how the portfolio was positioned before later 2025 quarter-end changes took more of the attention.
- Research
Berkshire Hathaway Q2 2025 Historical Ownership Review: What the Portfolio Looked Like Before the 2025 Rebuild
BERKSHIRE HATHAWAY INC's 2025Q2 filing provides a clean baseline for understanding how the portfolio was positioned before later 2025 quarter-end changes took more of the attention.
- Research
ALLIANCEBERNSTEIN L.P. Q3 2025 Historical Ownership Review: What the Portfolio Looked Like Before Q4
ALLIANCEBERNSTEIN L.P.'s 2025Q3 filing offers a clean baseline for understanding how its better-known Q4 positioning evolved.
- Research
Capital International Investors Q3 2025 Historical Ownership Review: What the Portfolio Looked Like Before Q4
Capital International Investors's 2025Q3 filing offers a clean baseline for understanding how its better-known Q4 positioning evolved.
- Research
Capital Research Global Investors Q3 2025 Historical Ownership Review: What the Portfolio Looked Like Before Q4
Capital Research Global Investors's 2025Q3 filing offers a clean baseline for understanding how its better-known Q4 positioning evolved.