Here’s a summary of the most significant insider transactions disclosed on Monday, December 8, 2025.
TOP BUYS
Adverum Biotechnologies (NASDAQ:ADVM) CEO, President and Director Laurent Fischer made a substantial investment in the company, purchasing a total of 128,699 shares worth $553,916. The transactions occurred in two parts: 11,085 shares at an average price of $4.24 on December 5, and 117,614 shares at an average price of $4.31 on December 8. Following these purchases, Fischer now directly owns 201,513 shares, including 1,200 shares acquired through the company’s Employee Stock Purchase Plan.
Adverum Biotechnologies (NASDAQ:ADVM) Chief Operating Officer Peter Soparkar also demonstrated confidence in the company by purchasing 50,000 shares on December 5, 2025. The shares were acquired at a weighted-average price of $4.22, with prices ranging from $4.18 to $4.24, for a total transaction value of $211,000. Following this purchase, Soparkar now directly owns 80,189 shares. This insider buying comes as Adverum’s stock has shown strong performance, up 46.8% over the past six months despite weak financial health indicators.
Annovis Bio, Inc. (NASDAQ:ANVS) Director Michael B Hoffman reported purchasing a total of 45,000 shares worth $193,794 on December 8, 2025. The director acquired 30,000 shares at $4.3398 per share ($130,194) and 15,000 shares at $4.24 per share ($63,600). Following these transactions, Hoffman directly owns 2,574,739 shares of the company. The insider buying comes as ANVS shares have shown strong momentum with a 40.5% price return over the past six months.
LINDE PLC (NYSE:LIN) Chief Executive Officer Lamba Sanjiv acquired 2,520 shares on December 8, 2025, at a weighted average price of $396.68, with prices ranging from $396.39 to $397.00. The total transaction value was $999,633, slightly above the current trading price of $390.09. Following the transaction, Lamba directly owns 90,794.191 shares. This purchase comes at a time when Linde shows good overall financial health with particularly strong profit metrics.
Texas Pacific Land Corp (NYSE:TPL) ten percent owner Horizon Kinetics Asset Management LLC purchased 1 share at $921.79 on December 5, 2025. Following this transaction, Horizon Kinetics directly owns 1,162,580 shares of TPL. The company boasts impressive gross profit margins of 94.13% and has maintained dividend payments for 12 consecutive years.
TOP SELLS
Diamondback Energy, Inc. (NASDAQ:FANG) Director Charles Alvin Meloy sold 377,911 shares at $138.61 per share on December 4, 2025, for a total value of $52,382,243. In addition, Meloy transferred 124,835 shares indirectly via Wolfrock Energy, LLC to trusts for the benefit of his children at no cost.
W.W. Grainger, Inc. (NYSE:GWW) Chairman and CEO Donald G. Macpherson sold 26,302 shares on December 4 and 5, 2025, for approximately $25.9 million. The sales occurred at prices ranging from $962.93 to $978.41 under a Rule 10b5-1 trading plan adopted on September 4, 2025. These transactions come as GWW trades near its 52-week low, down 18.35% over the past year.
Snowflake Inc. (NASDAQ:SNOW) Director Michael L. Speiser sold 50,346 shares on December 5, 2025, at weighted average prices ranging from $230.13 to $233.07, generating total proceeds of approximately $11.7 million. The transactions involved sales of shares held both directly and indirectly through various trusts and a limited partnership. This selling activity comes as SNOW shares have declined 9.21% over the past week.
Eos Energy Enterprises (NASDAQ:EOSE) Director Russell Monoki Stidolph recently sold shares in two separate transactions totaling approximately $11.4 million. On December 5, 2025, Stidolph sold 500,000 shares at $14.99 per share, followed by 30,767 shares on December 8, 2025, at prices ranging from $14.80 to $15.45.
Kymera Therapeutics, Inc. (NASDAQ:KYMR) Chief Medical Officer Jared Gollob sold 49,807 shares on December 8, 2025, for a total of $4,371,832. The sales were executed at prices ranging from $87.37 to $92.19. On the same day, Gollob also exercised options to acquire 49,307 shares at $5.33 per share. The transactions come as Kymera’s stock has shown remarkable momentum, with a 41% return over the last week and a 98% surge over the past six months.
Why Monitor Insider Activity
Tracking insider transactions provides valuable insights into how a company’s executives and directors view their own stock’s prospects. Significant insider buying often signals confidence in the company’s future performance, while substantial selling might raise questions about future growth or valuation concerns. However, investors should remember that insiders sell for many reasons unrelated to company outlook, including diversification, tax planning, or personal financial needs. The most reliable signals come from patterns of insider behavior rather than isolated transactions.
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