{"schema_version":"secwatch.filing_event.v1","accession":"0000776867-22-000017","form_type":"8-K","ticker":"WTM","cik":"0000776867","company_name":"WHITE MOUNTAINS INSURANCE GROUP LTD","filed_at":"2022-12-21T23:59:59+00:00","discovered_at":"2026-05-14T18:03:53.547998+00:00","generated_at":"2026-06-21T01:12:22.978982+00:00","sec_items":["8.01"],"event_type":"other_material","sentiment":"positive","materiality_score":0.7,"calibrated_materiality_score":0.7,"confidence":"high","headline":"White Mountains leads $250M reinsurance sidecar Outrigger Re for Ark","bullets":["Outrigger Re Ltd. formed as a Bermuda special purpose insurer with $250M total capital.","White Mountains contributes $205M; Aquiline Capital and Enstar (ESGR) join as investors.","Sidecar provides quota-share reinsurance on Ark Bermuda's global property catastrophe portfolio.","Coverage effective January 1, 2023, capitalizing on hard property cat reinsurance market.","TigerRisk acted as structuring agent; Sidley Austin and Conyers Dill provided legal counsel."],"urls":{"canonical":"https://secwatch.observer/filing/0000776867-22-000017","json":"https://secwatch.observer/filing/0000776867-22-000017.json","markdown":"https://secwatch.observer/filing/0000776867-22-000017.md","text":"https://secwatch.observer/filing/0000776867-22-000017.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/776867/000077686722000017/0000776867-22-000017-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/776867/000077686722000017/wtm-20221221.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-06-21T01:12:22.978982+00:00"},"review":{"review_status":"machine_generated","human_reviewed":false,"corrected":false,"correction_note":null,"correction_timestamp":null,"superseded_by":null,"related_filings":[]},"source_grounded_claims":[],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}