--- title: He Ran Symantec and Chaired Microsoft. Now John Thompson Sells $600K in Rubrik Stock Every Month. type: news slug: thompson-symantec-microsoft-rubrik-228m canonical_url: https://13finsight.com/news/thompson-symantec-microsoft-rubrik-228m published_at: 2026-03-04T10:33:48.090Z updated_at: 2026-03-23T07:04:53.950Z author: Alex Rivera author_title: Breaking News Editor author_url: https://13finsight.com/authors/alex-rivera word_count: 732 locale: en source: 13F Insight --- # He Ran Symantec and Chaired Microsoft. Now John Thompson Sells $600K in Rubrik Stock Every Month. > John W. Thompson has filed 2,034 insider transactions across seven public companies over two decades. His latest chapter: a clockwork monthly selling program at cybersecurity firm Rubrik. John W. Thompson has one of the most unusual insider trading records in corporate America. Over two decades, the veteran tech executive has filed 2,034 Form 4 transactions across seven public companies — from running Microsoft’s board as Chairman to selling $227 million in Rubrik’s predecessor Symantec. Now, at 76, he’s executing a textbook monthly liquidation of his Rubrik stake: convert shares, sell roughly $600,000, repeat on the first business day of every month. His career total: $228 million in sales and $16 million in purchases across SYMC, MSFT, RBRK, UPS, NiSource, Seagate, and Illumina. The Monthly Rubrik Machine Since Rubrik’s IPO in April 2024, Thompson has executed the same pattern on the first trading day of every month: convert 9,009 Class B shares to Class A, then sell them at market. The amounts vary only with Rubrik’s stock price. DateShares SoldAvg PriceProceeds Mar 2, 202613,500$53.30$723K Dec 1, 20259,009$69.02$619K Nov 3, 20259,009$75.55$680K Oct 1, 20259,009$83.07$746K May 1, 20259,009$71.45$644K Apr 1, 20259,009$60.19$542K Mar 3, 20259,009$63.18$569K Feb 3, 20259,009$70.98$639K Jan 14, 20259,009$64.70$583K The March 2026 sale broke the pattern slightly: Thompson exercised 11,000 options at $4.38 per share (his original pre-IPO strike price) and sold 13,500 shares rather than the usual 9,009. At $53 per share, he netted roughly $723,000 — the options exercise alone representing a 1,100% return on paper. The Seven-Company Trail What makes Thompson’s filing record remarkable is its breadth. Most insiders file at one or two companies. Thompson spans seven: CompanyTickerRolePeriodTransactionsShares BoughtShares Sold SymantecSYMCCEO & Chairman2003–20111,688325,00010,214,119 MicrosoftMSFTChairman2012–202313523,1940 RubrikRBRKDirector2024–present1010121,608 UPSUPSDirector2003–20138717,9213,584 NiSourceNIDirector2003–20051800 SeagateSTXDirector2004–20101000 IlluminaILMNDirector2018–2022500 The contrast between Microsoft and Symantec is striking. At Symantec, where Thompson served as CEO, he sold over 10 million shares — essentially his entire compensation over eight years. At Microsoft, where he served as the independent Chairman who helped select Satya Nadella as CEO in 2014, he never sold a single share. All 135 Microsoft transactions were stock awards that he held. The Symantec Chapter: $227 Million Thompson joined Symantec as CEO in 1999, following a 28-year career at IBM. During his tenure, he transformed Symantec from a consumer antivirus company into an enterprise security giant through the $13.5 billion acquisition of Veritas Software in 2005. He stepped down as CEO in 2009 and remained Chairman until 2011. Throughout this period, Thompson filed 1,688 transactions — overwhelmingly sales. He sold 10.2 million shares, bought 325,000, and collected $227 million in proceeds. Symantec was later acquired by Broadcom in 2019 for $10.7 billion, validating the enterprise pivot Thompson engineered. Why Rubrik Matters Now Rubrik went public in April 2024 at $32 per share, raising $752 million. The cybersecurity and data protection company has since grown its revenue to over $900 million annually, though it remains unprofitable. Thompson holds a pre-IPO stake through trusts, with approximately 845,000 indirect shares as of late 2025. His monthly selling pattern is consistent with a 10b5-1 pre-arranged trading plan — the same mechanism used by most corporate insiders to avoid timing questions. At the current pace of ~9,000 shares per month, his indirect holdings would take roughly 7-8 years to fully liquidate. Institutional holders of Rubrik include Vanguard Group and BlackRock, both of which hold significant positions in the cybersecurity company. Key Facts MetricValue Career transactions2,034 across 7 companies Career sells$227.5 million Career buys$15.9 million Companies filed atSYMC, MSFT, RBRK, UPS, NI, STX, ILMN Microsoft shares soldZero Rubrik monthly cadence~9,009 shares on 1st business day RBRK option strike$4.38 (pre-IPO) Current RBRK holdings (indirect)~845,000 shares Full profileView all transactions What to Watch Rubrik’s next monthly conversion — Thompson’s 9,009-share sell on the first business day of April 2026 will signal whether the pattern continues or the March acceleration (13,500 shares) becomes the new baseline. Rubrik lockup and vesting schedules — As a pre-IPO board member, Thompson’s remaining ~845K indirect shares vest on a rolling schedule. Monitor whether conversion sizes increase as more tranches unlock. Microsoft board composition — Thompson stepped down as Chairman in 2021 but may still hold unvested awards. Any future MSFT Form 4 filing would be the first sale in his 11-year history with the company. Illumina board activity — Thompson served on Illumina’s board through the contentious Grail acquisition battle. Any new filings would signal re-engagement with the genomics company. Trust restructuring pace — Thompson holds Rubrik shares across multiple entities. The January 2026 conversion of 55,000 shares between trusts suggests ongoing estate planning that may change the selling cadence. --- Source: 13F Insight — https://13finsight.com/news/thompson-symantec-microsoft-rubrik-228m Author: Alex Rivera — https://13finsight.com/authors/alex-rivera Last updated: 2026-03-23T07:04:53.950Z