---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-220479"
form_type: "8-K"
ticker: "BTC"
cik: "0002015034"
company_name: "Grayscale Bitcoin Mini Trust ETF"
filed_at: "2025-09-26T23:59:59+00:00"
generated_at: "2026-05-17T05:37:17.419117+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.55
calibrated_materiality_score: 0.55
confidence: "high"
source: SEC EDGAR
---

# Grayscale Bitcoin Mini Trust adds Anchorage Digital as secondary Bitcoin custodian for risk management

## Summary
- On Sept 25, 2025, Trust entered Second Amendment to add Anchorage Digital Bank N.A. as custody provider for Bitcoin holdings.
- Coinbase remains primary custodian; portion of Bitcoin to be held at Anchorage not yet determined by Sponsor.
- Anchorage will store private keys in cold storage, reducing online hacking risk compared to hot storage.
- Agreement includes indemnification obligations and requirement for Anchorage to maintain insurance.
- Addition reflects Sponsor's ongoing risk management approach given Trust's growing size.

## SEC filing metadata
- accession: 0001193125-25-220479
- form_type: 8-K
- ticker: BTC
- cik: 0002015034
- company_name: Grayscale Bitcoin Mini Trust ETF
- filed_at: 2025-09-26T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.55
- calibrated_materiality_score: 0.55
- confidence: high
- sec_items: 1.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/2015034/000119312525220479/0001193125-25-220479-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/2015034/000119312525220479/btc-20250926.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-220479
- JSON: https://secwatch.observer/filing/0001193125-25-220479.json
- Plain text: https://secwatch.observer/filing/0001193125-25-220479.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.