NYDIG Analyzes $1.26B BlackRock IBIT Block Trade as Urgent Exit, Not Basis Unwind

A single, massive off-exchange sale of BlackRock’s spot Bitcoin ETF IBIT on May 26 looks like a fast exit by a concentrated holder — not a routine basis-trade unwind, according to NYDIG. In its May 29 weekly Bitcoin digest, NYDIG’s Global Head of Research Greg Cipolaro dissected the $1.26 billion block trade and concluded the tape, holder data, ETF flows and CME futures activity point to an urgent liquidation. At 10:30:34 ET on May 26, one counterparty sold 29.21 million IBIT shares through FINRA/Nasdaq TRF Carteret at $43.16 a share. That price was $1.01 below the prevailing market quote of $44.17 — a 2.3% concession equal to roughly $29.5 million. Why that matters: the size of the block exceeded every disclosed 13F holder’s reported IBIT position as of March 31, required an unusually large price concession, and wasn’t accompanied by the surge in CME futures activity you would expect if someone were simultaneously unwinding a delta-neutral basis position, NYDIG said. “The evidence is most consistent with a large directional holder exiting a concentrated position rather than a contemporaneous basis-trade unwind,” the note states. Market context bolsters that view. The IBIT sale came after six straight sessions of net outflows from U.S. spot Bitcoin ETFs beginning May 15, a stretch that saw the category lose about $1.55 billion and IBIT alone account for roughly $1.1 billion. Bitcoin’s technical picture had also weakened: a failed rally into the descending 200-day moving average near $82k in early May gave way to a pullback, while the 14-day RSI slipped from around 70 into the mid-30s — conditions that likely fed ETF outflows ahead of the block trade. Microstructure clues point to urgency. Volume in IBIT accelerated sharply in the minutes before the block: between 10:16 and 10:28 the ETF moved from $43.81 to an intraday high of $44.24, with 10:26–10:27 and 10:27–10:28 printing about 822,000 and 702,000 shares respectively — roughly three to four times normal activity. The block was reported as an off-exchange TRF trade, carried a Rule 611 trade-through exemption, and was designated an Intermarket Sweep Order — all hallmarks of a privately negotiated execution that prioritizes certainty of fill over price improvement. A small trade seconds earlier printed at $44.17, confirming the $43.16 level was specific to the block rather than a market-wide move. IBIT briefly rebounded to about $44.06 within a minute, then slid later in the session and closed at $42.99. NYDIG pushed back on the basis-unwind theory with math. A 29.21 million-share IBIT stake corresponds to roughly 18,500 BTC of exposure — about 3,700 CME Bitcoin futures contracts. Total CME bitcoin futures volume that day was around 8,630 contracts; yet the 10:30–10:31 minute only saw 91 contracts and the adjacent minute 93. Even looking at 10:30–11:00, futures activity totaled only about 1,070 contracts. “A simultaneous basis unwind of this size would have represented approximately 43% of total daily CME volume and likely produced a visible spike in futures activity,” NYDIG said. “No such activity occurred.” NYDIG also cautioned against equating IBIT’s reported $720 million of net redemptions across May 26–27 with this block trade. ETF creations and redemptions can mask simultaneous gross activity, and IBIT’s reported NAVs on those dates ($42.955 and $42.431) were both below the $43.16 block price. The seller’s identity remains unknown. Public data can’t definitively say whether the exit was forced by redemptions or risk limits, or was a discretionary decision. What’s clear, NYDIG noted, is that one sophisticated holder paid nearly $30 million in price concession for speed and certainty. At press time, BTC was trading near $72,891.