CoinDesk
A $1.26 billion block sale of BlackRock's iShares Bitcoin Trust on May 26 was almost certainly a rapid exit by a single large holder rather than an arbitrage unwind, according to an analysis published by NYDIG. The transaction moved 29.21 million IBIT shares off-exchange at $43.16, a $1.01 discount to IBIT's then-market price of $44.17 — a 2.3% concession worth roughly $29.5 million in execution cost.
NYDIG's global head of research Greg Cipolaro argued the size of that discount is the giveaway. "The size of the trade, the 2.3% execution discount, the absence of corresponding CME futures activity, and the limited universe of potential sellers collectively weigh against the view that the transaction represented a contemporaneous basis-trade unwind," he wrote. The IBIT position equalled exposure on roughly 3,700 CME bitcoin futures contracts, yet only 91 futures contracts traded in the minute the block was executed, with no volume spike.
Why it matters
The basis-trade hypothesis was the comfortable read: a hedge fund unwinding a spot-futures leg would explain a billion-dollar block without anyone actually bearish on bitcoin. NYDIG is rejecting that comfort on three grounds — discount too wide, futures too quiet, seller pool too narrow. The IBIT position exceeded the disclosed holdings of every named 13F filer, which narrows the candidate list to institutions not required to disclose, sovereigns, or estate/treasury desks.
The trade was reported through the FINRA/Nasdaq TRF Carteret facility, the standard venue for privately negotiated off-exchange block trades. Accepting a $29.5 million haircut to clear size in minutes signals the seller valued certainty of execution over price optimisation — a profile that fits risk-management-driven selling, a margin call, or a discretionary de-risking far better than a basis unwind.
Market impact
The sale landed during the longest sustained ETF outflow streak of the cycle.
Frequently asked questions
-
What was the $1.26B IBIT block sale on May 26?
A privately negotiated off-exchange transaction moved 29.21 million IBIT shares at $43.16 — a $1.01 discount to the then-market price of $44.17, a 2.3% concession worth roughly $29.5 million in execution cost.
-
Why does NYDIG think it wasn't a basis-trade unwind?
NYDIG's Greg Cipolaro cited three reasons: the 2.3% discount was too wide for a basis trade, only 91 CME bitcoin futures contracts traded in the execution minute against ~3,700 contracts of equivalent exposure, and the position exceeded every disclosed 13F IBIT holder.
-
How does the block sale fit into broader ETF outflow trends?
The sale landed during a streak of daily net outflows across US spot bitcoin ETFs from May 15 through May 29. Category assets fell from $107.75 billion to $94.17 billion, and IBIT alone shed roughly $720 million across May 26–27.
-
Who could the seller be?
NYDIG noted the IBIT position exceeded every disclosed 13F filer's holdings, narrowing the candidate list to institutions not required to disclose, sovereign desks, or estate/treasury desks. Public data cannot confirm whether the sale was redemption-driven, risk-management-driven, or discretionary de-risking.
-
What is the broader macro context for the sale?
Bitcoin is down 16% year-to-date while equities and commodities have rallied, and BTC has slipped to the 13th-largest asset by market cap as capital rotates toward AI and precious metals. The block sale sits inside that broader risk-off rotation.
CoinTelegraph
Altcoin Daily
WuBlockchain
WatcherGuru
Lookonchain
TheBlock