secwatch.observer — SEC 8-K summary
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Issuer:     Grayscale Bitcoin Trust ETF (GBTC)
CIK:        0001588489
Form:       8-K
Filed at:   2026-03-16T23:59:59+00:00
Accession:  0001193125-26-108382
Event type: other_material
Sentiment:  neutral
Materiality: 0.40
Item codes: 8.01
LLM model:  deepseek-v4-flash:cloud@v2

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

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/1588489/000119312526108382/0001193125-26-108382-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/1588489/000119312526108382/gbtc-20260316.htm
  HTML page:      https://secwatch.observer/filing/0001193125-26-108382

License: Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer