---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-24-119507"
form_type: "8-K"
ticker: "GBTC"
cik: "0001588489"
company_name: "Grayscale Bitcoin Trust ETF"
filed_at: "2024-10-31T23:59:59+00:00"
generated_at: "2026-05-30T07:26:17.974953+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.35
calibrated_materiality_score: 0.35
confidence: "high"
source: SEC EDGAR
---

# Grayscale Bitcoin Trust adds Bullish to its index pricing constituents, effective Oct 27

## Summary
- CoinDesk Bitcoin Price Index (XBX) added Bullish as a constituent trading platform as of Oct 27, 2024.
- No platforms were removed; the index now includes Coinbase, Kraken, Bitstamp, Crypto.com, LMAX Digital, and Bullish.
- The change may affect the calculation of the Index Price used for the Trust's net asset value.
- The Index Provider can adjust venues at any time and conducts scheduled quarterly reviews.

## SEC filing metadata
- accession: 0000950170-24-119507
- form_type: 8-K
- ticker: GBTC
- cik: 0001588489
- company_name: Grayscale Bitcoin Trust ETF
- filed_at: 2024-10-31T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.35
- calibrated_materiality_score: 0.35
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1588489/000095017024119507/0000950170-24-119507-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1588489/000095017024119507/gbtc-20241027.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-24-119507
- JSON: https://secwatch.observer/filing/0000950170-24-119507.json
- Plain text: https://secwatch.observer/filing/0000950170-24-119507.txt

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