White Mountains Insurance Group Ltd reports

Location
23 South Main Street, Suite 3 B, Hanover, NH
State of incorporation
Bermuda
Fiscal year end
December 31
Data updated at
11/6/2024, 08:19 AM
Form type Sec Links Description Filing date Reporting date
10-Q Report | Data 10-Q Nov 6, 2024 Sep 30, 2024
8-K Report | Data 8-K Nov 6, 2024 Nov 6, 2024
10-Q Report | Data 10-Q Aug 7, 2024 Jun 30, 2024
8-K Report | Data 8-K Aug 7, 2024 Aug 7, 2024
8-K Report | Data 8-K Jun 7, 2024 Jun 7, 2024
8-K Report | Data 8-K May 23, 2024 May 23, 2024
SC 13D/A Report AMENDMENT NO. 4 May 9, 2024
10-Q Report | Data 10-Q May 9, 2024 Mar 31, 2024
8-K Report | Data 8-K May 9, 2024 May 9, 2024
SC 13D/A Report SC 13D/A May 3, 2024
8-K Report | Data 8-K Apr 10, 2024 Apr 10, 2024
10-K Report | Data 10-K Feb 26, 2024 Dec 31, 2023
8-K Report | Data 8-K Feb 23, 2024 Feb 22, 2024
SC 13G/A Report SCHEDULE 13G/A Feb 13, 2024
SC 13G/A Report Feb 12, 2024
SC 13G/A Report MS AMENDMENT Feb 9, 2024
SC 13G/A Report SEC SCHEDULE 13G Feb 9, 2024
8-K Report | Data 8-K Feb 7, 2024 Feb 7, 2024
8-K Report | Data 8-K Jan 3, 2024 Jan 2, 2024
SC 13D/A Report SC 13D/A Jan 3, 2024
8-K Report | Data 8-K Dec 21, 2023 Dec 21, 2023
10-Q Report | Data 10-Q Nov 6, 2023 Sep 30, 2023
8-K Report | Data 8-K Nov 6, 2023 Nov 6, 2023
SC 13D/A Report SC 13D/A Nov 2, 2023
8-K Report | Data 8-K Oct 20, 2023 Oct 19, 2023
10-Q Report | Data 10-Q Aug 7, 2023 Jun 30, 2023
8-K Report | Data 8-K Aug 7, 2023 Aug 7, 2023
SC 13D Report Jun 30, 2023
SC 13G/A Report Jun 8, 2023
8-K Report | Data 8-K Jun 6, 2023 Jun 6, 2023
8-K Report | Data 8-K May 25, 2023 May 25, 2023
8-K Report | Data 8-K May 25, 2023 May 25, 2023
10-Q Report | Data 10-Q May 9, 2023 Mar 31, 2023
8-K Report | Data 8-K May 9, 2023 May 9, 2023
SC 13G/A Report SCHEDULE 13G/A Mar 10, 2023
10-K Report | Data 10-K Feb 27, 2023 Dec 31, 2022
8-K Report | Data 8-K Feb 23, 2023 Feb 22, 2023
SC 13G Report Feb 14, 2023
SC 13G Report SC 13G Feb 10, 2023
SC 13G Report SEC SCHEDULE 13G Feb 10, 2023
SC 13G/A Report MS AMENDMENT Feb 10, 2023
SC 13G/A Report SCHEDULE 13G/A Feb 9, 2023
SC 13G Report Feb 8, 2023
8-K Report | Data 8-K Feb 7, 2023 Feb 7, 2023
SC 13G/A Report SEC SCHEDULE 13G Feb 6, 2023
8-K Report | Data 8-K Dec 21, 2022 Dec 21, 2022
10-Q Report | Data 10-Q Nov 7, 2022 Sep 30, 2022
8-K Report | Data 8-K Nov 7, 2022 Nov 7, 2022
8-K Report 8-K Aug 8, 2022 Aug 8, 2022
10-Q Report | Data 10-Q Aug 8, 2022 Jun 30, 2022
8-K Report | Data 8-K Aug 5, 2022 Aug 1, 2022
8-K Report | Data 8-K Jun 10, 2022 Jun 10, 2022
8-K Report | Data 8-K May 26, 2022 May 26, 2022
8-K Report | Data 8-K May 26, 2022 May 26, 2022
8-K Report | Data 8-K May 10, 2022 May 9, 2022
SC 13G/A Report May 6, 2022
10-Q Report | Data 10-Q May 6, 2022 Mar 31, 2022
8-K Report | Data 8-K May 6, 2022 May 6, 2022
8-K Report | Data 8-K Apr 1, 2022 Mar 31, 2022
10-K Report | Data 10-K Feb 28, 2022 Dec 31, 2021
SC 13G/A Report SC 13G/A Feb 14, 2022
SC 13G/A Report MS AMENDMENT Feb 11, 2022
SC 13G/A Report SCHEDULE 13G/A Feb 10, 2022
SC 13G/A Report Feb 9, 2022
8-K Report | Data 8-K Feb 8, 2022 Feb 8, 2022
SC 13G/A Report SEC SCHEDULE 13G Feb 4, 2022
SC 13G/A Report MS AMENDMENT Dec 10, 2021
8-K Report | Data 8-K Dec 2, 2021 Nov 29, 2021
10-Q Report | Data 10-Q Nov 8, 2021 Sep 30, 2021
8-K Report | Data 8-K Nov 8, 2021 Nov 8, 2021
8-K Report | Data 8-K Oct 12, 2021 Oct 10, 2021
8-K Report | Data 8-K Sep 13, 2021 Sep 8, 2021
8-K Report | Data 8-K Aug 13, 2021 Aug 11, 2021
10-Q Report | Data 10-Q Aug 6, 2021 Jun 30, 2021
8-K Report | Data 8-K Aug 6, 2021 Aug 6, 2021
8-K Report | Data 8-K Jul 19, 2021 Jul 13, 2021
8-K Report | Data 8-K Jun 29, 2021 Jun 29, 2021
8-K Report | Data 8-K Jun 4, 2021 Jun 4, 2021
8-K Report | Data 8-K May 28, 2021 May 27, 2021
10-Q Report | Data 10-Q May 10, 2021 Mar 31, 2021
8-K Report | Data 8-K May 10, 2021 May 10, 2021
10-K/A Report | Data 10-K/A Mar 30, 2021 Dec 31, 2020
8-K/A Report | Data 8-K/A Mar 16, 2021 Jan 1, 2021
10-K Report | Data 10-K Feb 26, 2021 Dec 31, 2020
SC 13G Report WHITE MOUNTAIN Feb 12, 2021
SC 13G Report SC 13G Feb 12, 2021
SC 13G Report Feb 10, 2021
SC 13G/A Report SCHEDULE 13G/A Feb 10, 2021
8-K Report | Data 8-K Feb 5, 2021 Feb 5, 2021
SC 13G/A Report SEC SCHEDULE 13G Feb 3, 2021
8-K Report | Data 8-K Jan 4, 2021 Jan 1, 2021
8-K/A Report | Data 8-K/A Dec 21, 2020 Dec 9, 2020
8-K Report | Data 8-K Dec 21, 2020 Dec 16, 2020
8-K Report | Data 8-K Dec 15, 2020 Dec 14, 2020
8-K Report | Data 8-K Dec 10, 2020 Dec 9, 2020
8-K Report | Data 8-K Dec 1, 2020 Nov 30, 2020
8-K Report | Data 8-K Nov 6, 2020 Nov 6, 2020
10-Q Report | Data 10-Q Nov 6, 2020 Sep 30, 2020
8-K Report | Data 8-K Oct 1, 2020 Oct 1, 2020
10-Q Report | Data 10-Q Aug 7, 2020 Jun 30, 2020
8-K Report | Data 8-K Aug 7, 2020 Aug 7, 2020
8-K Report | Data 8-K May 22, 2020 May 21, 2020
8-K Report | Data 8-K May 8, 2020 May 8, 2020
10-Q Report | Data 10-Q May 8, 2020 Mar 31, 2020
8-K Report | Data 8-K Apr 9, 2020 Apr 7, 2020
10-K/A Report | Data 10-K/A Mar 30, 2020 Dec 31, 2019
8-K Report | Data 8-K Mar 23, 2020 Mar 20, 2020
SC 13G/A Report SCHEDULE 13G/A Mar 6, 2020
10-K Report | Data 10-K Mar 2, 2020 Dec 31, 2019
SC 13G/A Report SCHEDULE 13G/A Feb 12, 2020
SC 13G/A Report ROBECO INVESTMENT MANAGEMENT INC. Feb 11, 2020
8-K Report | Data 8-K Feb 5, 2020 Feb 5, 2020
SC 13G/A Report SEC SCHEDULE 13G Jan 27, 2020
10-Q Report | Data 10-Q Nov 6, 2019 Sep 30, 2019
8-K Report | Data 8-K Nov 6, 2019 Nov 6, 2019
8-K Report | Data 8-K Aug 30, 2019 Aug 29, 2019
10-Q Report | Data 10-Q Aug 6, 2019 Jun 30, 2019
8-K Report | Data 8-K Aug 6, 2019 Aug 6, 2019
8-K Report 8-K Jun 28, 2019 Jun 28, 2019
8-K Report 8-K Jun 7, 2019 Jun 7, 2019
8-K Report 8-K May 24, 2019 May 24, 2019
10-Q Report | Data 10-Q May 6, 2019 Mar 31, 2019
8-K Report 8-K May 6, 2019 May 6, 2019
8-K Report 8-K Apr 4, 2019 Apr 4, 2019
8-K Report 8-K Mar 1, 2019 Feb 27, 2019
10-K Report | Data 10-K Feb 27, 2019 Dec 31, 2018
8-K Report 8-K Feb 26, 2019 Feb 26, 2019
8-K Report 8-K Feb 14, 2019 Feb 14, 2019
SC 13G/A Report Feb 14, 2019
SC 13G Report ROBECO INVESTMENT MANAGEMENT INC. Feb 14, 2019
SC 13G Report SEC SCHEDULE 13G Feb 12, 2019
SC 13G/A Report Feb 11, 2019
8-K Report 8-K Feb 6, 2019 Feb 6, 2019
8-K Report 8-K Feb 4, 2019 Feb 4, 2019
8-K Report 8-K Jan 7, 2019 Jan 3, 2019
10-Q Report | Data 10-Q Nov 5, 2018 Sep 30, 2018
8-K Report 8-K Nov 5, 2018 Nov 5, 2018
8-K Report 8-K Aug 24, 2018 Aug 23, 2018
10-Q Report | Data 10-Q Aug 7, 2018 Jun 30, 2018
8-K Report 8-K Aug 7, 2018 Aug 7, 2018
8-K Report 8-K Jun 8, 2018 Jun 8, 2018
8-K Report 8-K May 29, 2018 May 24, 2018
8-K Report 8-K May 11, 2018 May 11, 2018
10-Q Report | Data 10-Q May 2, 2018 Mar 31, 2018
8-K Report 8-K May 2, 2018 May 2, 2018
8-K Report 8-K Apr 10, 2018 Apr 10, 2018
8-K Report 8-K Apr 2, 2018 Mar 31, 2018
8-K Report 8-K Mar 2, 2018 Mar 1, 2018
10-K Report | Data 10-K Feb 28, 2018 Dec 31, 2017
SC 13G/A Report Feb 14, 2018
SC 13G/A Report Feb 8, 2018
8-K Report 8-K Feb 7, 2018 Feb 7, 2018
SC 13G/A Report SC 13G/A Jan 29, 2018
10-Q Report | Data 10-Q Nov 8, 2017 Sep 30, 2017
8-K Report 8-K Nov 8, 2017 Nov 8, 2017
SC 13G/A Report Oct 10, 2017
8-K Report 8-K Sep 28, 2017 Sep 28, 2017
8-K Report CURRENT REPORT Sep 15, 2017 Sep 15, 2017
8-K/A Report 8-K/A Aug 28, 2017 Aug 24, 2017
8-K Report 8-K Aug 25, 2017 Aug 24, 2017
8-K Report 8-K Aug 17, 2017 Aug 17, 2017
SC 13G/A Report Aug 9, 2017
10-Q Report | Data 10-Q Aug 4, 2017 Jun 30, 2017
8-K Report | Data 8-K Aug 4, 2017 Aug 4, 2017
8-K Report 8-K Jun 30, 2017 Jun 26, 2017
8-K Report 8-K May 31, 2017 May 25, 2017
8-K Report 8-K May 8, 2017 May 8, 2017
8-K Report May 2, 2017 May 2, 2017
8-K Report 8-K May 2, 2017 May 2, 2017
10-Q Report | Data 10-Q May 2, 2017 Mar 31, 2017
8-K Report 8-K May 2, 2017 May 2, 2017
8-K Report 8-K Mar 6, 2017 Mar 6, 2017
10-K Report | Data 10-K Feb 27, 2017 Dec 31, 2016
SC 13G/A Report Feb 10, 2017
SC 13G/A Report Feb 7, 2017
SC 13G/A Report Feb 7, 2017
8-K Report 8-K Feb 7, 2017 Feb 7, 2017
10-Q Report | Data 10-Q Nov 2, 2016 Sep 30, 2016
8-K Report 8-K Nov 2, 2016 Nov 2, 2016
SC 13G/A Report Oct 11, 2016
10-Q Report | Data 10-Q Aug 3, 2016 Jun 30, 2016
8-K Report 8-K Aug 3, 2016 Aug 3, 2016
8-K Report 8-K Jul 21, 2016 Jul 21, 2016
8-K Report 8-K Jun 9, 2016 Jun 9, 2016
8-K Report 8-K May 31, 2016 May 26, 2016
8-K Report | Data 8-K May 2, 2016 May 2, 2016
10-Q Report | Data 10-Q May 2, 2016 Mar 31, 2016
8-K Report 8-K Apr 22, 2016 Apr 19, 2016
SC 13G/A Report SC 13G/A Apr 20, 2016
8-K Report | Data 8-K Apr 18, 2016 Apr 18, 2016
8-K Report | Data 8-K Apr 7, 2016 Apr 7, 2016
8-K Report 8-K Mar 30, 2016 Mar 30, 2016
10-K Report | Data 10-K Feb 29, 2016 Dec 31, 2015
SC 13G Report Feb 11, 2016
SC 13G/A Report WTM AS OF 12/31/2015 Feb 9, 2016
8-K Report 8-K Feb 5, 2016 Feb 5, 2016
8-K Report 8-K Feb 4, 2016 Feb 1, 2016
SC 13G/A Report Feb 2, 2016
10-Q Report | Data 10-Q Nov 2, 2015 Sep 30, 2015
8-K Report 8-K Nov 2, 2015 Nov 2, 2015
10-Q Report | Data 10-Q Aug 3, 2015 Jun 30, 2015
8-K Report CURRENT REPORT Jul 30, 2015 Jul 24, 2015
8-K Report 8-K Jul 27, 2015 Jul 27, 2015
8-K Report CURRENT REPORT Jul 27, 2015 Jul 24, 2015
8-K Report 8-K Jun 12, 2015 Jun 12, 2015
8-K Report 8-K Jun 8, 2015 Jun 8, 2015
8-K Report 8-K Jun 1, 2015 May 28, 2015
10-Q Report | Data 10-Q May 4, 2015 Mar 31, 2015
8-K Report 8-K May 4, 2015 May 4, 2015
8-K Report 8-K Apr 10, 2015 Apr 10, 2015
8-K Report 8-K Mar 26, 2015 Mar 26, 2015
8-K Report 8-K Mar 2, 2015 Feb 25, 2015
10-K Report | Data 10-K Feb 27, 2015 Dec 31, 2014
SC 13G/A Report Feb 13, 2015
SC 13G/A Report SC 13G/A Feb 12, 2015
SC 13G/A Report WTM AS OF 12/31/2014 Feb 11, 2015
8-K Report 8-K Feb 10, 2015 Feb 10, 2015
SC 13G/A Report Feb 3, 2015
8-K Report 8-K Dec 23, 2014 Dec 23, 2014
10-Q Report | Data 10-Q Oct 29, 2014 Sep 30, 2014
8-K Report 8-K Oct 29, 2014 Oct 29, 2014
8-K Report 8-K Oct 14, 2014 Oct 13, 2014
10-Q Report | Data 10-Q Jul 29, 2014 Jun 30, 2014
8-K Report 8-K Jul 29, 2014 Jul 29, 2014
8-K Report 8-K Jun 10, 2014 Jun 10, 2014
8-K Report 8-K May 27, 2014 May 22, 2014
10-Q Report | Data 10-Q Apr 28, 2014 Mar 31, 2014
8-K Report 8-K Apr 28, 2014 Apr 28, 2014
8-K Report 8-K Mar 12, 2014 Mar 12, 2014
8-K Report 8-K Mar 10, 2014 Mar 10, 2014
8-K Report 8-K Mar 4, 2014 Feb 26, 2014
10-K Report | Data 10-K Feb 28, 2014 Dec 31, 2013
SC 13G/A Report SC 13G/A Feb 14, 2014
SC 13G Report WTM AS OF 12/31/2013 Feb 12, 2014
SC 13G/A Report Feb 12, 2014
8-K Report 8-K Feb 7, 2014 Feb 7, 2014
SC 13G/A Report AMENDMENT NO. 1 Feb 5, 2014
SC 13G/A Report AMENDMENT NO. 1 Feb 5, 2014
SC 13G/A Report Jan 31, 2014
8-K Report 8-K Dec 20, 2013 Dec 20, 2013
SC 13G Report Dec 10, 2013
10-Q Report | Data 10-Q Oct 28, 2013 Sep 30, 2013
8-K Report 8-K Oct 28, 2013 Oct 28, 2013
SC 13G Report SCHEDULE 13G Sep 17, 2013
8-K Report 8-K Aug 22, 2013 Aug 22, 2013
8-K Report 8-K Aug 21, 2013 Aug 21, 2013
10-Q Report | Data 10-Q Jul 30, 2013 Jun 30, 2013
8-K Report 8-K Jul 30, 2013 Jul 30, 2013
8-K Report 8-K Jun 7, 2013 Jun 7, 2013
8-K Report 8-K May 28, 2013 May 23, 2013
10-Q Report | Data 10-Q Apr 29, 2013 Mar 31, 2013
8-K Report 8-K Apr 29, 2013 Apr 29, 2013
8-K Report 8-K Apr 4, 2013 Apr 3, 2013
SC 13G Report SCHEDULE 13G Mar 18, 2013
8-K Report 8-K Mar 1, 2013 Feb 27, 2013
10-K Report | Data 10-K Mar 1, 2013 Dec 31, 2012
SC 13G/A Report SC 13G/A Feb 13, 2013
SC 13G/A Report SC 13G/A Feb 13, 2013
SC 13G/A Report SC 13G/A Feb 13, 2013
8-K Report 8-K Feb 5, 2013 Feb 5, 2013
SC 13G/A Report Jan 30, 2013
10-Q Report | Data 10-Q Oct 30, 2012 Sep 30, 2012
8-K Report 8-K Oct 30, 2012 Oct 30, 2012
8-K Report 8-K Oct 18, 2012 Oct 18, 2012
10-Q Report | Data 10-Q Jul 27, 2012 Jun 30, 2012
8-K Report 8-K Jul 27, 2012 Jul 27, 2012
8-K Report 8-K Jun 13, 2012 Jun 13, 2012
8-K Report 8-K May 30, 2012 May 24, 2012
10-Q Report | Data 10-Q Apr 27, 2012 Mar 31, 2012
8-K Report 8-K Apr 27, 2012 Apr 27, 2012
8-K Report 8-K Apr 5, 2012 Apr 5, 2012
10-K Report | Data 10-K Feb 28, 2012 Dec 31, 2011
8-K Report 8-K Feb 24, 2012 Feb 22, 2012
SC 13G/A Report Feb 6, 2012
SC 13G/A Report SC 13G/A Feb 3, 2012
SC 13G/A Report SC 13G/A Feb 3, 2012
8-K Report 8-K Feb 3, 2012 Feb 3, 2012
SC 13G/A Report SC 13G/A Feb 1, 2012
SC 13D/A Report SC 13D/A Jan 20, 2012
8-K Report 8-K Nov 22, 2011 Nov 16, 2011
8-K Report 8-K Nov 18, 2011 Nov 17, 2011
10-Q Report | Data 10-Q Oct 28, 2011 Sep 30, 2011
8-K Report 8-K Oct 28, 2011 Oct 28, 2011
8-K/A Report 8-K/A Oct 12, 2011 May 25, 2011
8-K Report 8-K Oct 7, 2011 Oct 7, 2011
8-K Report 8-K Sep 23, 2011 Sep 22, 2011
8-K Report CURRENT REPORT Aug 17, 2011 Aug 17, 2011
10-Q Report | Data 10-Q Jul 29, 2011 Jun 30, 2011
8-K Report 8-K Jul 29, 2011 Jul 29, 2011
8-K Report 8-K Jun 22, 2011 Jun 22, 2011
8-K Report 8-K May 31, 2011 May 25, 2011
8-K Report 8-K May 18, 2011 May 17, 2011
8-K Report 8-K Apr 29, 2011 Apr 29, 2011
10-Q Report | Data 10-Q Apr 29, 2011 Mar 31, 2011
8-K Report 8-K Apr 29, 2011 Apr 29, 2011
8-K Report 8-K Mar 1, 2011 Feb 24, 2011
10-K Report | Data 10-K Feb 28, 2011 Dec 31, 2010
SC 13G/A Report SEC FILING Feb 14, 2011
SC 13G/A Report WTM AS OF 12/31/10 Feb 10, 2011
8-K Report 8-K Feb 4, 2011 Feb 4, 2011
SC 13G/A Report SC 13G/A Jan 31, 2011
SC 13G/A Report Jan 28, 2011
8-K Report 8-K Oct 29, 2010 Oct 27, 2010
10-Q Report | Data 10-Q Oct 29, 2010 Sep 30, 2010
8-K Report 8-K Oct 29, 2010 Oct 29, 2010
10-Q Report | Data 10-Q Jul 30, 2010 Jun 30, 2010
8-K Report 8-K Jul 30, 2010 Jul 30, 2010
8-K Report 8-K May 28, 2010 May 26, 2010
8-K Report 8-K May 18, 2010 May 18, 2010
10-Q Report 10-Q Apr 29, 2010 Mar 31, 2010
8-K Report 8-K Apr 29, 2010 Apr 29, 2010
8-K Report 8-K Apr 27, 2010 Apr 27, 2010
8-K Report 8-K Apr 15, 2010 Apr 15, 2010
8-K Report 8-K Mar 29, 2010 Mar 23, 2010
8-K Report 8-K Mar 2, 2010 Feb 24, 2010
10-K Report 10-K Feb 26, 2010 Dec 31, 2009
SC 13G Report SEC FILING Feb 12, 2010
SC 13G Report WTM AS OF 12/31/2009 Feb 11, 2010
8-K Report 8-K Feb 3, 2010 Feb 3, 2010
SC 13G/A Report SC 13G/A Jan 27, 2010
SC 13G/A Report Jan 22, 2010
10-Q Report 10-Q Oct 30, 2009 Sep 30, 2009
10-Q Report 10-Q Jul 31, 2009 Jun 30, 2009
10-Q Report 10-Q May 1, 2009 Mar 31, 2009
10-K Report 10-K Feb 27, 2009 Dec 31, 2008
10-Q Report 10-Q Oct 31, 2008 Sep 30, 2008
10-Q Report 10-Q Aug 1, 2008 Jun 30, 2008
10-Q Report 10-Q May 2, 2008 Mar 31, 2008
10-K Report 10-K Feb 29, 2008 Dec 31, 2007