A $1.26 billion block sale of BlackRock's iShares Bitcoin Trust (IBIT) on May 26 was almost certainly a large investor rushing for the exit, not a hedge-fund basis-trade unwind — that's the conclusion from NYDIG's global head of research, Greg Cipolaro. The seller offloaded 29.21 million shares off-exchange at $43.16, accepting a $1.01 discount to IBIT's prevailing market price of $44.17 — a 2.3% concession that cost roughly $29.5 million in execution losses. NYDIG's read: only someone who valued speed and certainty over price maximization takes that kind of haircut.
The basis-trade theory — that the block represented a simultaneous unwind of spot IBIT exposure against short CME bitcoin futures — doesn't hold up under scrutiny. The IBIT position was equivalent to roughly 3,700 CME contracts, yet only 91 futures contracts traded during the exact minute the block was executed.
CoinDesk