| Byrne John JosephFormer 10% Owner · 5 transactions | — | 637.1K†as of Feb 2013 | — | 4.3K | — |
| Berkshire Hathaway Inc +3 co-filers10% owner · 1 transaction | — | 89.3Kas of Oct 2008 | — | — | 1.63M |
| Barrette Raymond Joseph ReneChief Executive Officer, Director · 222 transactions | — | 58.9K†as of Mar 2017 | 208.7K | 20.4K | 11.0K |
| Gillespie John DaviesDirector · 14 transactions | — | 53.0K†as of Feb 2015 | 5.1K | — | — |
| Foy David ThomasChief Financial Officer · 11 transactions | — | 30.6K†as of May 2017 | 32.4K | — | — |
| Seelig Robert LawrenceEVP & General Counsel · 71 transactions | — | 20.9K† | 37.5K | 1.2K | 7.0K |
| Rountree George ManningChief Executive Officer, Director · 56 transactions | — | 19.4K† | 44.0K | — | 10.6K |
| Waters Allan LewisCEO - Sirius Int'l Ins. Group, Director · 18 transactions | — | 18.2K†as of Feb 2015 | 17.6K | 4.6K | — |
| Campbell Reid TarltonDirector · 70 transactions | — | 10.7K† | 35.4K | — | 13.2K |
| Fass Steve ElliottDirector · 1 transaction | — | 9.6K†as of Feb 2007 | — | — | — |
| Cochran Robert PhillipsDirector · 9 transactions | — | 8.0Kas of May 2011 | 600 | — | 17.6K |
| Davis Morgan WDirector · 110 transactions | — | 7.7K†as of Dec 2022 | 10.3K | 10.1K | 21.4K |
| Caffrey Liam PChief Executive Officer, Director · 6 transactions | — | 6.1K† | 4.9K | — | — |
| Hildreth MichaelaMD & Chief Accounting Officer · 17 transactions | — | 4.3K† | 3.2K | — | 200 |
| Brouillette YvesDirector · 28 transactions | — | 4.1Kas of May 2019 | 4.1K | 3.0K | 3.4K |
| Bazos Frank REVP and Head of M&A · 2 transactions | — | 3.6Kas of Feb 2020 | 3.6K | — | — |
| Palmer Jess BrianChief Accounting Officer · 37 transactions | — | 3.5K†as of Jan 2021 | 8.9K | — | 1.8K |
| Hicks Weston MDirector · 10 transactions | — | 2.9K | 936 | 1.0K | — |
| Holiday Edith EDirector · 13 transactions | — | 2.8Kas of May 2020 | 2.6K | — | — |
| Harrison Giles EPresident · 3 transactions | — | 2.7K† | 2.7K | — | — |
| Frinquelli Angelo MichaelDirector · 20 transactions | — | 2.6K†as of Nov 2017 | 2.0K | 600 | 100 |
| Tolman Gary CharlesDirector · 10 transactions | — | 2.6K†as of May 2018 | 1.7K | 2 | 139 |
| Chokel Charles BergenCFO - White Mountains Re Group · 3 transactions | — | 2.1K†as of Jun 2008 | 1.6K | — | — |
| Tanner David AllenDirector · 13 transactions | — | 2.0K | 1.7K | 500 | — |
| Choksi Mary CDirector · 10 transactions | — | 2.0K | 2.0K | — | — |
| Papamichael Michael AChief Financial Officer · 2 transactions | — | 2.0K† | 500 | — | — |
| Oberting Kernan VManaging Director · 9 transactions | — | 1.8K†as of Jan 2016 | 4.0K | — | 1.9K |
| Gelston Philip ADirector · 11 transactions | — | 1.7K | 1.9K | — | 165 |
| Linker DavidChief Investment Officer · 3 transactions | — | 1.4K†as of Mar 2017 | 3.0K | — | — |
| Gillespie George Joseph IIIDirector · 4 transactions | — | 1.4Kas of May 2010 | 400 | — | — |
| Clark Howard Longstreth JrDirector · 5 transactions | — | 1.2Kas of May 2013 | 800 | — | — |
| Smith Lowndes AndrewDirector · 21 transactions | — | 1.1Kas of Dec 2019 | 2.4K | — | 2.3K |
| Dillon MargaretDirector · 6 transactions | — | 1.1K | 1.1K | — | — |
| Shank Suzanne F.Director · 6 transactions | — | 1.0K | 1.0K | — | — |
| Carlson Peter MDirector · 10 transactions | — | 852 | 1.6K | — | 200 |
| Yi StevenDirector · 3 transactions | — | 525as of May 2025 | 495 | — | — |
| Berkowitz Bruce RDirector · 10 transactions | — | 300as of Apr 2010 | 300 | — | — |
| Chu JohnDirector · 1 transaction | — | 200 | 135 | — | — |
| Klar StephenDirector · 1 transaction | — | 0 | 113 | — | — |