Research

Insider Selling and 10b5-1 Plans: Identifying Real Red Flags

A practical 10b5-1 filter that helps investors distinguish routine insider selling from meaningful risk signals.

CEO Buys vs Option Exercises: How to Read Form 4 Correctly

How to separate true insider conviction from mechanical option-related flows in Form 4 filings.

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.

Sanders Capital Exits $1.6B in China and Oil, Opens $2.3B Salesforce Bet: The Q4 2025 Value Pivot

Sanders Capital's $86.8B portfolio exits Alibaba, Halliburton, and Schlumberger while opening a $2.3B Salesforce position and doubling its Lockheed Martin stake — a decisive Q4 2025 value pivot.

Mubadala's $17.5B Q4 Filing: 90% GlobalFoundries, Quantum Computing Bets, and a $631M Bitcoin Play

Abu Dhabi's Mubadala sovereign wealth fund holds 90% of its $17.5B portfolio in GlobalFoundries, added $631M in Bitcoin via IBIT, and opened positions in 4 quantum computing stocks in Q4 2025.

February 27, 2026

Windacre Doubled Its Portfolio to $9.3B in One Quarter and Made Roper Technologies Its Biggest Bet Ever

Snehal Amin's Windacre Partnership surged from $4.4B to $9.3B in a single quarter, deploying $4.9B across 7 new positions headlined by a brand-new $1.38B bet on Roper Technologies that the fund had never previously held.

Soros Pivots to Energy and AI Infrastructure - Q4 2025 Portfolio Surges 23%

Soros Fund Management's Q4 2025 13F reveals a bold pivot to energy options (XOP, XLE) and AI infrastructure (CoreWeave, Kodiak AI), with the portfolio surging 23% to $8.6B across 244 assets.

Bridgewater Doubles Its Portfolio to $27.4B After a Record 33% Year - Q4 2025 13F Breakdown

Bridgewater Associates doubled its 13F portfolio to $27.4B in Q4 2025, expanding to 1,040 holdings after Ray Dalio's exit and a record 33% return in its Pure Alpha fund.

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.

Bridgewater Doubles Its Portfolio to $27.4B After a Record 33% Year — Q4 2025 13F Breakdown

Bridgewater Associates doubled its 13F equity portfolio to $27.4B in Q4 2025, adding 549 new holdings. After Ray Dalio's formal exit and a record 33% Pure Alpha return, we break down the fund's systematic, diversified approach.

Soros Pivots to Energy & AI Infrastructure — Q4 2025 Portfolio Surges 23% to $8.6 Billion

Soros Fund Management's Q4 2025 13F reveals a bold pivot to energy ETFs (XOP, XLE puts) and AI infrastructure (CoreWeave, Kodiak AI), with AUM surging 23% to $8.6 billion. 115 new positions opened, heavy convertible bond exposure, and a massive energy hedge signal Soros's signature asymmetric macro strategy.

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.

February 26, 2026

Feb 26Research

Armitage Sold Every Share of META and Built a $1.36B Amazon Position in Its Place: Inside Egerton’s Q4 2025 Portfolio Reconstruction

John Armitage exited 9 positions including META ($397M) and Progressive, then opened 10 new ones led by a $1.36B Amazon bet at 14.8% of portfolio. More than half of Egerton’s $9.2B portfolio is entirely new.

Feb 26Research

Farallon Slashed $2.5B in Credit Hedges and Built a $6.8B Biotech Empire While Dumping Bitcoin: Inside the Q4 2025 Pivot

Tom Steyer’s Farallon Capital cut its HYG put position by 80% — from $3.17B to $645M — while deploying billions into Revolution Medicines, Natera, and BridgeBio. The $42B fund also dumped 77% of its Bitcoin ETF.

February 25, 2026

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.

State Street Q4 2025: Low Turnover, Higher AUM, and a Core Beta Rebuild

STATE STREET CORP reported $2980.91B in Q4 2025 13F assets with top-10 concentration at 31.36%. We break down what changed and what retail investors can act on.

BlackRock Added 81 Net Holdings in Q4 2025 While Keeping a Mega-Cap Core

BlackRock, Inc. reported $5916.35B in Q4 2025 13F assets with top-10 concentration at 30.44%. We break down what changed and what retail investors can act on.

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.

Pershing Square's Q4 2025 Pivot: $2.22B in Amazon, $1.76B in Meta, and a 25.2% Portfolio Expansion

Pershing Square expanded its 13F portfolio by 25.2% quarter-over-quarter in Q4 2025, adding Amazon and Meta as major new positions while Brookfield became the top holding.

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.