Monday’s insider buys and sells: Group 1 Automotive leads activity

Here’s a roundup of the most significant insider trading activity disclosed for Monday, October 26, 2026, across US public markets.

Top insider buys

Group 1 Automotive Inc. (NASDAQ:GPI) saw the largest insider purchase of the day as Conifer Management, L.L.C., a 10% owner and director, acquired common stock totaling $24,232,208 across multiple transactions between October 22 and October 26, 2026. The purchases involved shares acquired at prices ranging from $226.00 to $249.2967 per share. Following these transactions, Conifer Management, L.L.C. indirectly holds 2,012,290 shares of Group 1 Automotive common stock. The buying comes as the stock trades near its 52-week low of $224.65, down 28% over the past six months. According to InvestingPro analysis, the stock appears undervalued at current levels, with shares trading at a P/E ratio of 10.46. This insider activity aligns with an InvestingPro Tip noting that management has been aggressively buying back shares—one of 11 key insights available to subscribers.

Corebridge Financial, Inc. (NASDAQ:CRBG) attracted significant insider interest as Nippon Life Insurance Co., a director and 10% owner, purchased 246,440 shares of the company’s common stock on October 22, 2026. The transactions totaled approximately $8,662,932, with prices ranging from $34.62 to $35.55 per share. These purchases were executed under a Rule 10b5-1 trading plan adopted by Nippon Life on August 7, 2026. Following these transactions, Nippon Life Insurance Co. beneficially owns a total of 130,667,106 shares of Corebridge Financial common stock. The purchase comes as CRBG trades near its 52-week high of $35.64, with shares up 34% over the past six months. According to InvestingPro analysis, the stock appears fairly valued at current levels. This total includes 130,633,835 shares held directly by Nippon Life and an additional 33,271 shares held by Nissay Asset Management Corporation, a direct wholly owned subsidiary of Nippon Life.

Optimum Communications, Inc. (NASDAQ:OPTU) saw insider buying from Neil S. Subin, a director and 10% owner, who recently purchased Class A Common Stock in the company, with transactions totaling approximately $1,163,551. These acquisitions took place on October 22 and 23, 2026, with prices ranging from $0.5196 to $0.612 per share. The insider buying comes as the stock trades at $0.72, down 67% over the past year. According to InvestingPro analysis, OPTU currently appears overvalued relative to its Fair Value of $0.63. On October 22, 2026, Mr. Subin acquired 2,164,383 shares of Class A Common Stock at a price of $0.5196 per share. The following day, October 23, 2026, an additional 63,624 shares were purchased at $0.612 per share.

Korro Bio, Inc. (NASDAQ:KRRO) received backing from Lynx1 Capital Management LP, a 10% owner and director, which recently acquired common stock in the company totaling $884,751. The purchases, which occurred over several days in late October 2026, involved shares bought at weighted average prices ranging from $9.6764 to $12.1061 per share, increasing the investment firm’s stake in the biotechnology company. The timing of these purchases coincides with a strong rally in KRRO shares, which posted a 35% return over the past week, bringing the current stock price to $12.02. According to InvestingPro data, the stock has shown significant volatility with a beta of 2.36, and the platform offers 10 additional ProTips for investors analyzing this biotechnology company. The transactions involved the acquisition of 79,809 shares of Korro Bio common stock.

Gentherm Inc (NASDAQ:THRM) saw insider confidence from Paul Mascarenas, a director, who purchased 20,000 shares of the company’s common stock on October 23, 2026. The transactions totaled $532,600. The shares were acquired at prices ranging from $26.00 to $26.80, with a weighted average price of $26.63 per share. The purchase comes as Gentherm stock trades near its 52-week low of $25.31, down 16% year-to-date, with shares currently at $28.59. Following these transactions, Mr. Mascarenas directly holds 22,677 shares of Gentherm common stock. According to InvestingPro analysis, the stock appears undervalued at current levels, with the company offering a notable 7.24% dividend yield.

Top insider sells

Intuitive Surgical Inc. (NASDAQ:ISRG) saw Gary Guthart, a director, sell 20,095 shares of common stock for a total value of approximately $9.08 million. The transactions, which occurred on October 23, 2026, were executed under a pre-arranged Rule 10b5-1 trading plan set to expire on June 15, 2027. The shares were sold at prices ranging from $444.04 to $458.10 per share, with a weighted average sale price of $451.6117. Following these sales, Mr. Guthart directly holds 1,204,530 shares of Intuitive Surgical common stock. Additionally, shares are held indirectly through trusts for his daughter and son, each holding 26,247 shares. The insider sale comes as Intuitive Surgical trades at $450.08, near InvestingPro’s Fair Value estimate, with the company maintaining a market capitalization of $156 billion. The medical device maker has demonstrated strong momentum with 20% revenue growth, though it trades at a P/E ratio of 54.16.

Charles River Laboratories International, Inc. (NASDAQ:CRL) experienced significant activity from James C. Foster, a Director, who engaged in stock transactions on October 22, 2026, according to a recent filing. Mr. Foster acquired 24,042 shares of common stock at a price of $244.41 per share, totaling $5,876,105. Concurrently, he sold 24,042 shares of the company’s common stock at $350.00 per share, for a total value of $8,414,700. This sale was executed pursuant to a Rule 10b5-1 trading plan, which was initially adopted on March 6, 2026. The timing of the sale comes as CRL shares trade near their 52-week high of $357.77, with the stock currently at $357.27. According to InvestingPro analysis, the stock appears overvalued relative to its Fair Value, placing it among the most overvalued stocks tracked by the platform.

Lam Research Corp (NASDAQ:LRCX) saw Timothy Archer, President and CEO, sell 31,400 shares of the company’s common stock on October 23, 2026, for a total value of $7,128,428. The shares were sold at a price of $227.02 each. The stock has since risen to $239.54, though it experienced a sharp 15.5% decline over the past week amid broader market volatility. The sale was executed pursuant to a Rule 10b5-1 trading plan, which Mr. Archer adopted on February 24, 2026.

United Therapeutics Corp (NASDAQ:UTHR) recorded a sale from Martine A. Rothblatt, Chairperson and CEO, who sold 9,500 shares of the company’s common stock on October 23, 2026, for a total value of approximately $5.54 million. The shares were sold at prices ranging from $577.6774 to $587.9997 per share. The sale comes as the stock trades near its 52-week high of $609.35, with shares delivering a strong 40% return over the past year. According to InvestingPro analysis, the stock currently appears overvalued relative to its Fair Value. The company maintains a market capitalization of $25.41 billion and trades at a P/E ratio of 21.02. The sale followed the exercise of 9,500 stock options on the same day, which were acquired at an exercise price of $117.76 per share, totaling approximately $1.12 million.

PACS Group Inc. (NASDAQ:PACS) experienced selling from Jason Hulse Murray, Co-Founder, CEO & Chairman, who sold common stock totaling $4,000,386 across multiple transactions in late October 2026, with prices ranging from $47.50 to $49.105 per share. These transactions were carried out under a pre-arranged Rule 10b5-1 trading plan, which Murray adopted on May 18, 2026. The sales occurred over two days. On October 22, 2026, Murray disposed of 13,696 shares of common stock at prices ranging from $47.50 to $47.65 per share. The following day, October 23, 2026, he completed two additional sales: 22,722 shares were sold at prices between $47.50 and $48.495 per share, and another 46,195 shares were sold at prices ranging from $48.50 to $49.105 per share. Following these transactions, Murray directly holds 54,188,200 shares of PACS Group common stock. The timing of these sales coincides with PACS trading near its 52-week high of $49.78, following a remarkable 285% return over the past year.

Monitoring insider trading activity provides valuable insights into how company executives and major shareholders view their stock’s prospects. While insider purchases can signal confidence in a company’s future performance, sales don’t necessarily indicate pessimism, as executives may sell shares for various personal financial reasons, including diversification or liquidity needs. However, patterns of significant buying or selling, especially when combined with other fundamental analysis, can help investors make more informed decisions about their portfolios.