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
Royal Bank of Canada's $615B Q4 Filing Holds 29,036 Positions — Including $12.5B of Its Own Stock and Rival Toronto-Dominion
Canada's largest bank filed a U.S. 13F with 29,036 positions, three S&P 500 ETFs in its top 5, $12.5B of its own stock (RY), and $11.9B of competitor Toronto-Dominion. Netflix shares surged 893% in one quarter.
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Capital International Investors' $638B Portfolio Puts Broadcom at #1 and Built a $2.5B Netflix Position in One Quarter
While most mega-filers lead with NVIDIA, Capital International Investors bets biggest on Broadcom at 7.7% of portfolio. They also increased Netflix shares by 710% in Q4 2025, added $3.4B in TotalEnergies, and exited Disney entirely.
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Dimensional Fund Advisors' $477B Q4 Portfolio: The Factor Investing Pioneer Holds 13,709 Stocks and Not a Single ETF
DFA — the firm that brought academic factor research to real portfolios — files 13,709 positions without a single ETF or index fund. Its Q4 2025 13F reveals a 17.9% top-5 concentration with Berkshire Hathaway, Exxon, and Visa in the top 15 — the anti-momentum portfolio built on Nobel Prize-winning research.
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Wellington Management's $571B Q4 Portfolio: The Stock Picker's Stock Picker Built a $14B Eli Lilly Position While Everyone Else Was Chasing AI
Wellington Management is the largest pure active manager in our database — no ETFs, no index funds. Its Q4 2025 13F reveals a $571B portfolio where healthcare rivals tech for attention: Lilly at $14.4B, Merck at $9.1B, and a Meta trim of 18% that goes against the passive consensus.
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Bank of America's $1.375T Q4 Filing: SPY Cut in Half, NVIDIA Trimmed 22%, and $26B in Vanguard ETFs Nobody Talks About
Bank of America's Q4 2025 13F reveals the last uncovered megabank: a $1.375 trillion portfolio with 28,105 positions, a 12.9% top-5 concentration that makes it the most diversified major bank filing, and a massive Vanguard ETF allocation that signals where Merrill Lynch clients actually park their money.
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Goldman Sachs' $811B Q4 Portfolio Puts Tesla in the Top 5 — Ahead of Alphabet, Amazon, and Meta
Goldman Sachs' Q4 2025 13F reveals an $811B portfolio where Tesla at $18.3B ranks #5 — above Alphabet, Amazon, and Meta. NVIDIA leads at $41.8B, but the real story is Goldman's $28.4B SPY position and what the flat QoQ growth signals.
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Fidelity's $1.96 Trillion Q4 Portfolio: Trimming Meta by $4.3 Billion While Doubling Down on Alphabet
FMR LLC's Q4 2025 13F reveals a $1.96T portfolio across 5,359 positions. The world's third-largest asset manager cut Meta by $4.3B and NVIDIA by $2.8B — but added $5.3B to Alphabet's two share classes. Here's what the rotation signals.
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How Zoom's CEO Sells 12,100 Shares Every Single Day — and Why It Hasn't Stopped
Eric Yuan has filed 1,506 Form 4 transactions since Zoom's 2019 IPO — converting and selling shares on a daily mechanical schedule. Career total: $1.3B sold, zero bought. He also quietly sits on the Intuit board.
- News
Carl Icahn Has $2.6B in IEP Unit Transfers Since 2003. The SEC Wanted to Know Why.
The legendary activist investor settled SEC charges over undisclosed pledges of Icahn Enterprises units — while the stock fell 85% from its peak. A breakdown of 410 transactions across 25 companies.
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Norway's $935B Sovereign Wealth Fund Put $62B in NVIDIA Alone: Inside Norges Bank's Q4 2025 US Equity Portfolio
Norges Bank Investment Management, managing the world's largest sovereign wealth fund, disclosed $935B in US equities for Q4 2025 — a 7.4% QoQ increase. NVIDIA leads at $62B (6.7% of portfolio), followed by Apple at $52B and Microsoft at $51B.
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Insider Cluster Buying: A Signal Framework for Retail Investors
A practical framework for identifying high-signal insider cluster buying events and filtering out low-information Form 4 noise.
- News
Lilly Endowment Sold $406M in Eli Lilly Stock in Six Weeks — And Still Owns $100B
The Lilly family's philanthropic endowment dumped 376,000 LLY shares worth $406 million between November and December 2025, yet its remaining 92.2 million shares are worth over $100 billion.
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Buffett Dumps 77% of Amazon in His Final Quarter as CEO - Berkshire Hathaway Q4 2025 13F Deep Dive
Berkshire Hathaway's Q4 2025 13F reveals Buffett slashed Amazon by 77%, continued trimming Apple and Bank of America, while adding to Chevron and Chubb — all in his final quarter as CEO.
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Buffett Dumps 77% of Amazon in His Final Quarter as CEO — Berkshire Hathaway Q4 2025 13F Deep Dive
Warren Buffett slashed Amazon by 77% in his final quarter as Berkshire Hathaway CEO, while adding to Chevron, Chubb, and Domino's. Deep dive into the $274.2B Q4 2025 13F filing.
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Soroban Tripled to $14.3B in One Quarter and Built a $2.3B Utility Sleeve Nobody Saw Coming: Inside Mandelblatt's Tech-Utility Barbell
Eric Mandelblatt's Soroban Capital deployed $9.2B in a single quarter — tripling AUM from $5.15B to $14.33B — while building a rare tech-utility barbell with MSFT and AMZN at the top and nine regulated utilities underneath.
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Vanguard's $6.90T Q4 2025 Filing: Mega-Cap Concentration With Broad-Market Breadth
VANGUARD GROUP INC reported $6897.68B in Q4 2025 13F assets with top-10 concentration at 31.23%. We break down what changed and what retail investors can act on.
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Castle Hook Dumped $1.35B in Bitcoin and Built an $8.4B Gold Fortress: Inside the Soros Alumnus's Macro Bet That Doubled Portfolio Size
Josh Donfeld's Castle Hook Partners exited Bitcoin entirely, built a 35% gold allocation, added $8.3B in equity puts, and grew 13F AUM 74% to $24.1B in Q4 2025 — the most dramatic macro pivot of filing season.
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Smead Capital's $4.8B Anti-AI Portfolio: 27.5% Housing, Zero Magnificent Seven, and a 15.5x P/E vs the Market's 27.7x
Smead Capital's Q4 2025 13F reveals a $4.8B portfolio with 27.5% in housing, 20.6% in banks, and just 2.2% in tech. At 15.5x P/E vs the S&P 500's 27.7x, Bill Smead is betting that overlooked value sectors will deliver the same alpha they did after similar discounts in 2015, 2020, and 2022.
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Q4 2025 13F: Bank Exposure Signals Institutions Can't Hide
A non-tech research note on interpreting bank exposure changes in Q4 2025 13F filings: rotation patterns, funding sources, and a checklist to avoid common 13F traps.
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70% of Icahn's $8.45B Sits in Two Energy Companies: Inside the Most Concentrated Non-Tech 13F in Q4 2025
Carl Icahn's Q4 2025 13F reveals extreme energy concentration — IEP and CVR Energy alone account for 70% of his $8.45B portfolio, with zero technology exposure and just 13 holdings.