White Mountains Insurance Group Ltd.

WTM·NYSE·$2129.17Share Price as of 11/2·$5BMarket Cap as of 11/2

Financials

10-QQ2 ended 06/30/2608/06/26 10-QQ1 ended 03/31/2605/06/26 10-KFY 202502/27/26 10-QQ3 ended 09/30/2511/06/25 10-QQ2 ended 06/30/2508/07/25

Disclosures

8-KCurrent report08/27/26 8-KCurrent report08/06/26 8-KCurrent report06/05/26 8-KCurrent report05/21/26 8-KCurrent report05/15/26

Prospectuses and Registrations

S-8 POSPost-effective amendment (S-8)12/30/20 S-8 POSPost-effective amendment (S-8)12/30/20 S-8 POSPost-effective amendment (S-8)12/30/20 S-8 POSPost-effective amendment (S-8)12/30/20 S-8 POSPost-effective amendment (S-8)12/30/20

Proxies

DEF 14ADefinitive proxy04/01/26 DEF 14ADefinitive proxy04/02/25 DEF 14ADefinitive proxy04/04/24 DEFA14AAdditional proxy materials05/10/23 DEFR14ADefinitive proxy (revised)04/06/23

Ownership

Form 4Insider transaction08/31/26 Form 3Initial insider ownership08/27/26 Form 4Insider transaction08/27/26 13F-HRInstitutional holdings08/12/26 Form 3Initial insider ownership05/22/26

Other

N-PXAnnual report of proxy voting record08/26/26 11-KEmployee stock purchase plan report06/30/26 ARSAnnual report to shareholders04/01/26 SC TO-I/ASC TO-I/A12/29/25 SC TO-I/ASC TO-I/A12/22/25