Grayscale Bitcoin Mini Trust ETF 8-K

What Happened

• Grayscale Investments Sponsors, LLC (the Sponsor) filed an 8‑K on March 16, 2026, announcing that effective April 1, 2026 the Grayscale Bitcoin Mini Trust ETF (BTC) will value the Bitcoin it holds for operational purposes using the CoinDesk Bitcoin Benchmark Rate. Prior to April 1, 2026 the Trust used the CoinDesk Bitcoin Price Index (XBX). The Trust’s NAV and NAV per share will be calculated using the new Index Price as of 4:00 p.m., New York time on each business day.

Key Details

• Effective date: April 1, 2026. Filing date: March 16, 2026. Sponsor: Grayscale Investments Sponsors, LLC.
• New index: CoinDesk Bitcoin Benchmark Rate (calculated every 5 seconds over 24 hours; volume‑weighted, outlier detection, inactivity adjustment, FX normalization). Prior index: CoinDesk Bitcoin Price Index (XBX).
• Constituent trading platforms included (as of March 16, 2026): Binance, Bitstamp by Robinhood, Bullish, Bybit, Crypto.com, Gate, Gemini, HashKey, Kraken, LMAX Digital, and OKX. Sponsor states these platforms meet licensing and AML/KYC expectations per the Index methodology.
• Fallback/cascading rules if the Index is unavailable: (1) contact Index Provider for price; (2) use Coin Metrics Real‑Time Rate (Secondary Index); (3) use the Trust’s principal market spot price; (4) Sponsor’s good‑faith estimate. Index License Agreement dated Feb 1, 2022 allows the Index Provider discretion to change methodology.

Why It Matters

• For investors, the change affects how BTC holdings are valued for NAV and NAV per share calculations starting April 1, 2026. The CoinDesk Benchmark Rate uses a multi‑venue, volume‑weighted algorithm and a defined fallback process, which the Sponsor says should reduce the impact of anomalous or manipulative activity on the Trust’s reported price. Any material methodology or constituent changes by the Index Provider will be disclosed in the Trust’s SEC reports.