---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-108382"
form_type: "8-K"
ticker: "GBTC"
cik: "0001588489"
company_name: "Grayscale Bitcoin Trust ETF"
filed_at: "2026-03-16T23:59:59+00:00"
generated_at: "2026-05-15T11:44:38.486592+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.4
calibrated_materiality_score: 0.4
confidence: "high"
source: SEC EDGAR
---

# Grayscale Bitcoin Trust to switch Bitcoin benchmark to CoinDesk Bitcoin Benchmark Rate on Apr 1

## Summary
- Effective April 1, 2026, GBTC will value Bitcoin using CoinDesk Bitcoin Benchmark Rate, replacing CoinDesk Bitcoin Price Index (XBX).
- New benchmark uses data from 11 exchanges: Binance, Bitstamp, Bullish, Bybit, Crypto.com, Gate, Gemini, HashKey, Kraken, LMAX Digital, OKX.
- Methodology includes volume weighting, outlier detection, inactivity adjustment, and manipulation resistance to mitigate fraud.
- If primary index is unavailable, cascading rules fall back to Coin Metrics Real-Time Rate, then principal market price, then Sponsor's estimate.
- The change is operational only; no immediate impact on Bitcoin holdings or share structure.

## SEC filing metadata
- accession: 0001193125-26-108382
- form_type: 8-K
- ticker: GBTC
- cik: 0001588489
- company_name: Grayscale Bitcoin Trust ETF
- filed_at: 2026-03-16T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.4
- calibrated_materiality_score: 0.4
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1588489/000119312526108382/0001193125-26-108382-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1588489/000119312526108382/gbtc-20260316.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-108382
- JSON: https://secwatch.observer/filing/0001193125-26-108382.json
- Plain text: https://secwatch.observer/filing/0001193125-26-108382.txt

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