Core Insights - Berkshire Hathaway disclosed a new position in New York Times Co with 5,065,744 shares in the fourth quarter ending December 31, 2025 [1] - The company clarified its positions within the Liberty Media ecosystem, maintaining its stake in Liberty Formula One with 3,018,555 shares [1] Portfolio Changes - The fourth quarter 13F filing revealed changes in existing stocks, highlighting the top decreased stakes by percentage [2] - Despite a decrease in the Apple position, it remains the largest holding in Berkshire Hathaway's investment portfolio [2]

Core Insights - Ark Invest, led by Cathie Wood, made significant trades including purchases of Advanced Micro Devices Inc. (AMD), Bullish Inc. (BLSH), and Figma Inc. (FIG), while selling shares of Tempus AI Inc. (TEM) [1] AMD Trade - Ark Fintech Innovation ETF (ARKF) acquired 25,899 shares of AMD, valued at approximately $4.1 million based on a closing price of $160.46 [2] - This acquisition occurs amid concerns regarding U.S. government investments in Intel Corp., which may lead to inefficiencies in the semiconductor sector [2] Bullish Inc. Trade - ARK Innovation ETF (ARKK) and ARK Next Generation Internet ETF (ARKW) collectively purchased 161,183 shares of Bullish, valued at about $8.3 million, with the stock closing at $51.36 [3] - Bullish recently raised $1.1 billion in its U.S. IPO and is expected to benefit from favorable conditions in the cryptocurrency market [4] - Analysts have mixed views on Bullish, with a Buy rating from Rosenblatt and a Neutral rating from JPMorgan [4] Tempus AI Trade - Ark Invest sold 167,598 shares of Tempus AI, valued at approximately $14.6 million based on a closing price of $87.04 [6] - This sale follows Tempus AI's recent FDA clearance for its AI-powered cardiac imaging platform [6] Figma Trade - ARKW purchased 109,678 shares of Figma, valued at about $5.9 million, with the stock closing at $53.67 [7] - Ark's continued investment in Figma indicates confidence in the company's long-term growth prospects despite recent earnings disappointments [7] Other Key Trades - Ark Invest made additional trades including buying shares of Airbnb Inc. (ABNB), Arcturus Therapeutics Holdings Inc. (ARCT), Intellia Therapeutics Inc. (NTLA), CRISPR Therapeutics AG (CRSP), and Beam Therapeutics Inc. (BEAM) [10]