Last week, an institutional investor executed the largest off-exchange transaction in the history of U.S. spot Bitcoin funds, shedding a $1.26 billion position in BlackRock’s iShares Bitcoin Trust (IBIT).
While the transaction has sparked intense debate on Wall Street, an analysis by NYDIG suggests the sale was a targeted, urgent withdrawal of a whale, and not the routine conclusion of a popular hedge fund arbitrage game.
According to the analysis, the entity paid a high price for immediate liquidity. It incurred nearly $30 million in execution costs alone to secure an exit before the broader digital asset market suffered a notable recession.
Insight into the IBIT megatrade
NYDIG noted that activity in BlackRock’s IBIT began to quietly accelerate after an early morning session of normal volume.
According to the company, the ETF’s share price rose from $43.81 to an intraday peak of $44.24 between 10:16 a.m. and 10:28 a.m. Eastern Time. Trading volume increased to three or four times the normal rate during this period, indicating that an executing broker was testing market liquidity and carefully preparing the tape for a mass placement.
Then, at exactly 10:30 am, the hammer fell.
A single seller dumped 29.21 million shares of IBIT in a privately negotiated off-exchange transaction. The block ended at $43.16 per share. Since the prevailing open market price at the time was $44.17, the seller accepted a 2.3% haircut on the spot. In dollar terms, that execution sentence cost the mysterious entity approximately $29.5 million.
Regulatory reporting codes associated with the trade illustrate the seller’s singular focus on speed. The transaction was printed on the FINRA/Nasdaq TRF Carteret, a facility used by broker-dealers to report dark pool and privately negotiated transactions.
Additionally, it had an Intermarket Sweep Order designation in addition to a Reg NMS trade-through exemption.
In plain English, these exemptions allow institutional players to avoid the requirement to seek the absolute best displayed price on multiple public exchanges, provided they take responsibility for meeting certain protected quotes.
This shows that the seller actively preferred the certainty of an immediate, joint exit over the possibility of a better price.
Debunking the arbitrage myth
When highly unusual billion-dollar imprints occur in crypto ETFs, market commentators typically opt for a common explanation: the basic trade.
This popular hedge fund strategy involves buying a spot ETF while shorting Bitcoin futures to reap returns from the price differences between the two.
However, NYDIG’s analysis identifies three different factors that dismantle basic development theory in this case.
First, the fundamental economies are not aligned. A basic trader relies on earning a small percentage return over time. Accepting an immediate loss of 230 basis points on the spot side of the trade would immediately evaporate much of the strategy’s expected annual return.
Unless faced with a catastrophic margin call, an arbitrage agency would obviously passively unwind its position over days or weeks to preserve capital.
Secondly, the structural urgency of trade is completely at odds with delta-neutral management. Intermarket sweep orders and deep block discounts are the hallmarks of a distressed or deeply condemned directional seller, not a market-neutral yield farmer.
Finally, the futures market provided the ultimate smoking gun. A block of 29.21 million shares in IBIT is equivalent to approximately 18,500 Bitcoin. If an arbitrageur were to exit a delta-neutral position of that size, they would have to simultaneously buy back approximately 3,700 Bitcoin futures contracts on the Chicago Mercantile Exchange (CME) to flatten their portfolio.
However, CME’s order book barely registered a heartbeat that day. At the exact time the ETF block crossed the line, only 91 futures contracts changed hands. During the entire half hour of trading, barely 1,000 contracts were executed.
Furthermore, a true basis settlement of this magnitude would have required nearly half of the CME’s total daily volume to have been absorbed in an instant, triggering a huge, highly visible spike in futures activity.
The total absence of such a spike therefore confirms that the seller was simply long Bitcoin and suddenly wanted out.
Who is the whale?
The size of the transaction alone leaves a remarkably short list of suspects.
NYDIG noted that the block trades exceeded the total holdings of all disclosed 13F investors in the first quarter of 2026, excluding authorized participants and market makers, who hold stocks solely for liquidity provision rather than investment purposes.
After a transaction of this size, analysts naturally look to funding flows to monitor its aftermath. IBIT recorded $192 million in net redemptions on May 26, followed by another $528 million on May 27.
However, market mechanisms suggest that these figures do not represent direct, immediate settlement of the whale shares.
Because the ETF’s net asset value closed at $42.95 on the day of the trade and at $42.43 the next day, which is well below the negotiated block execution price of $43.16, the counterparty purchasing the shares had no economic incentive to immediately redeem them from the issuer.
Doing so would have resulted in an immediate loss. Instead, the buyer likely incorporated the block into the stock and systematically distributed the shares to the secondary market over time.
The ultimate identity of the seller and his motive therefore remain shrouded in the opacity of off-exchange trading. It is impossible to definitively prove whether the whale was forced out due to strict internal risk limits or whether they made a discretionary bet that the crypto market was headed for a sustained downturn.
Market headwinds and institutional fatigue
After the trade on May 26, Bloomberg ETF analyst Eric Balchunas claimed that “the market has absorbed the selling well.”
However, the timing of the billions of dollars’ withdrawal proved proactive as May was a tough month for digital assets. Facts from CoinGlass showed that the top cryptocurrency lost almost 4% over the month and was trading near $73,000 at the end.
This price performance was exacerbated by the collapse of investor interest in spot Bitcoin ETFs.
NYDIG noted that U.S. funds were already on a six-day streak of consecutive outflows heading into the May 26 session. In that period alone, the sector lost $1.55 billion, with BlackRock’s IBIT taking most of the damage, losing around $1.1 billion.
By the end of May the damage had become even greater. According to data from SoSoValue, US-listed spot Bitcoin ETFs had total monthly outflows of $2.4 billion.
Due to continued selling pressure, total assets under management in the ETF category fell from more than $100 billion to $94.17 billion.