{"schema_version":"secwatch.filing_event.v1","accession":"0000950170-25-105826","form_type":"8-K","ticker":"GBTC","cik":"0001588489","company_name":"Grayscale Bitcoin Trust ETF","filed_at":"2025-08-08T23:59:59+00:00","discovered_at":"2026-05-14T18:02:44.441821+00:00","generated_at":"2026-05-17T16:35:54.699200+00:00","sec_items":["1.01","9.01"],"event_type":"other_material","sentiment":"neutral","materiality_score":0.45,"calibrated_materiality_score":0.45,"confidence":"high","headline":"Grayscale Bitcoin Trust adds Anchorage Digital as secondary Bitcoin custodian","bullets":["Entered custodial agreement with Anchorage Digital Bank N.A. on Aug 8, 2025 for Bitcoin custody.","Anchorage will store Bitcoin private keys in cold storage; Coinbase remains primary custodian.","Sponsor has not yet determined amount of Bitcoin to move to Anchorage.","Agreement also covers Grayscale Ethereum Trust ETF as additional client.","Anchorage is a national trust bank chartered by OCC; agreement includes indemnification and insurance."],"urls":{"canonical":"https://secwatch.observer/filing/0000950170-25-105826","json":"https://secwatch.observer/filing/0000950170-25-105826.json","markdown":"https://secwatch.observer/filing/0000950170-25-105826.md","text":"https://secwatch.observer/filing/0000950170-25-105826.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1588489/000095017025105826/0000950170-25-105826-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1588489/000095017025105826/gbtc-20250808.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-05-17T16:35:54.699200+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"}