Insider trading recap: September 21, 2026
On September 21, 2026, insiders filed 38 open-market purchases worth $352.7M across 34 companies, and 103 sales worth $601.4M, on SEC Form 4. The largest purchase was Berkshire Hathaway INC (10% Owner) buying $212.4M of LENNAR CORP /NEW/ (LEN) at an average $77.42 a share. The largest sale was Zhao Peng Jonathan (Chief Executive Officer, Director, 10% Owner) selling $110.0M of Kanzhun Ltd (BZ). 4 companies had several insiders buying on the same day: Grab Holdings Ltd (GRAB), GameStop Corp. (GME), REDWOOD TRUST INC (RWT).
The write-up, company by company: insider buying on September 21, 2026 · insider selling on September 21, 2026.
Biggest insider buys filed September 21, 2026
Open-market purchases, one row per Form 4, largest first.
| Company | Insider | Value | Shares | Avg price | Traded |
|---|---|---|---|---|---|
| LEN LENNAR CORP /NEW/ | Berkshire Hathaway INC 10% Owner | $212.4M | 2,743,529 | $77.42 | Sep 17, 2026 |
| GRAB Grab Holdings Ltd | Tan Anthony Ping Yeow Chief Executive Officer, Director | $29.9M | 10,350,000 | $2.89 | Sep 21, 2026 |
| GSAT Globalstar, Inc. | Monroe James III Director, 10% Owner | $29.8M | 361,600 | $82.52 | Sep 18, 2026 |
| GME GameStop Corp. | Cohen Ryan President, CEO and Chairman, Director | $26.4M | 1,150,680 | $22.94 | Sep 21, 2026 |
| LNBIX Lincoln Bain Capital Total Credit Fund | Lincoln Financial Investments Corp 10% Owner, Investment Adviser | $25.0M | 2,460,630 | $10.16 | Sep 17, 2026 |
| GPI GROUP 1 AUTOMOTIVE INC | Conifer Management, L.L.C. 10% Owner | $16.9M | 65,650 | $256.78 | Sep 17, 2026 |
| CRBG Corebridge Financial, Inc. | Nippon Life Insurance Co 10% Owner · 10b5-1 | $6.2M | 174,760 | $35.20 | Sep 17, 2026 |
| HELP Helus Pharma Inc. | Halstead Michael Chief Executive Officer | $1.3M | 100,000 | $13.47 | Sep 21, 2026 |
| CRM Salesforce, Inc. | Kirk David Blair Director | $999K | 4,176 | $239.33 | Sep 18, 2026 |
| GRAB Grab Holdings Ltd | Hungate Alexander Charles President and COO, Director | $867K | 299,571 | $2.89 | Sep 21, 2026 |
| PRTA PROTHENA CORP PUBLIC LTD CO | Scully William P 10% Owner | $843K | 100,000 | $8.43 | Sep 18, 2026 |
| GLP GLOBAL PARTNERS LP | Global GP LLC General Partner | $504K | 10,000 | $50.36 | Sep 17, 2026 |
| GME GameStop Corp. | Attal Alain Director | $402K | 17,500 | $22.97 | Sep 21, 2026 |
| BORR Borr Drilling Ltd | Morand De Oliveira Bruno Chief Executive Officer | $200K | 45,500 | $4.40 | Sep 18, 2026 |
| RTB RTB Digital, Inc. | Dorsett Jason Christopher 10% Owner | $197K | 19,000 | $10.36 | Sep 17, 2026 |
Several insiders buying the same stock
Companies where two or more insiders filed purchases this day. All cluster buys.
Biggest insider sales filed September 21, 2026
Selling has many routine reasons (taxes, diversification, planned 10b5-1 sales), so read these as context.
| Company | Insider | Value | Shares | Avg price | Traded |
|---|---|---|---|---|---|
| BZ Kanzhun Ltd | Zhao Peng Jonathan Chief Executive Officer, Director, 10% Owner | $110.0M | 15,170,000 | $7.25 | Sep 21, 2026 |
| ANET Arista Networks, Inc. | Bechtolsheim Andreas 10% Owner · 10b5-1 | $59.7M | 300,000 | $198.95 | Sep 17, 2026 |
| TWST Twist Bioscience Corp | Leproust Emily M. Chief Executive Officer, Director · 10b5-1 | $56.3M | 356,546 | $157.99 | Sep 17, 2026 |
| SNDK Sandisk Corp | Goeckeler David Chairman & CEO, Director · 10b5-1 | $53.3M | 33,841 | $1,574.21 | Sep 17, 2026 |
| DELL Dell Technologies Inc. | Silver Lake Partners IV, L.P. Director, 10% Owner | $30.7M | 52,488 | $585.77 | Sep 17, 2026 |
| GSAT Globalstar, Inc. | Lynch James F Director | $29.8M | 361,600 | $82.52 | Sep 18, 2026 |
| DELL Dell Technologies Inc. | Sl Spv-2, L.P. Director, 10% Owner | $27.1M | 46,253 | $585.91 | Sep 17, 2026 |
| SION Sionna Therapeutics, Inc. | Ra Capital Management, L.P. Director, 10% Owner | $21.8M | 3,448,811 | $6.33 | Sep 17, 2026 |
| WDAY Workday, Inc. | Duffield David A 10% Owner · 10b5-1 | $18.3M | 94,089 | $194.69 | Sep 18, 2026 |
| DELL Dell Technologies Inc. | Silver Lake Partners V DE (AIV), L.P. Director, 10% Owner | $15.6M | 26,553 | $585.91 | Sep 17, 2026 |
Grouped by the day the Form 4 reached SEC EDGAR. Values are shares times the reported price; a price far from the market close is treated as a typo and left out. Not investment advice.