An unknown entity offloaded $1.289 billion worth of BlackRock's IBIT — the largest U.S. spot bitcoin ETF by assets — in a single dark-pool block trade at 10:30 a.m. ET on May 27, 2026, per CoinDesk's reporting citing Galaxy Research head Alex Thorn, who called it the largest such trade he has ever observed in a spot bitcoin ETF.
Dark-pool trades are privately negotiated transactions between large counterparties, executed off public exchanges. They allow institutions to move substantial positions without telegraphing intent to the broader market or instantly moving the spot price. A block of this size — $1.289 billion in a single print — signals one entity making a high-conviction exit in a single decision, rather than a gradual unwind.
The trade fell on a day of broader institutional retreat from U.S.-listed spot bitcoin ETFs. IBIT processed net redemptions of $192.44 million on May 27, per CoinDesk citing SoSoValue data. Across the full set of 11 U.S. spot bitcoin ETFs, total net outflows for the day reached $334 million.
That one-day figure is part of a seven-consecutive-day outflow streak — the second-longest since spot BTC ETFs launched in January 2024 — that has pulled $1.88 billion out of the products combined, per CoinDesk. The two longer streaks on record both ran eight days: late August through early September 2024, which totalled $1.2 billion in outflows, and February 2025, which totalled $3.3 billion.
An important distinction: the dark-pool trade and the net outflow figure measure different things. The $1.289 billion block is a single transaction; buyers may have absorbed part of it within IBIT's creation-redemption mechanism. The $192.44 million net redemption figure reflects the final tally — all IBIT share creation and redemption activity for the full day — and confirms that sellers outpaced buyers by that margin.
Bitcoin itself has been under pressure. The largest cryptocurrency was trading under $77,000 at the time of CoinDesk's reporting, down from highs above $82,000 on May 6, per CoinDesk Markets data.
Historically, sustained institutional-scale block exits in ETFs have preceded continued price softness, though causality runs both ways: large holders often time exits to coincide with weakening momentum rather than drive it. What matters here is the persistence of the signal. Seven straight days of net outflows, capped by a single-session block trade of unprecedented size in this product class, represents a sustained directional conviction — not a one-day anomaly.
Note on sourcing: Alex Thorn's original X post could not be retrieved directly due to X authentication requirements. Attribution is per CoinDesk's contemporaneous reporting citing Thorn. The direct post URL is unavailable to this reporter without authenticated X access. SoSoValue's direct data page was blocked (Cloudflare 403). The $192.44M IBIT net redemption figure is attributed to CoinDesk as primary reporting outlet citing SoSoValue as its data source.