An unidentified institutional investor executed a historic off-exchange trade, selling a $1.26 billion position in BlackRock's iShares Bitcoin Trust (IBIT) last week. The transaction, which incurred nearly $30 million in execution costs, was a strategic move to secure liquidity before a broader market decline. The sale involved a 29.21 million-share block trade, executed at $43.16 per share, below the market price of $44.17, indicating a 2.3% discount. Analysis by NYDIG suggests the trade was not a typical hedge fund arbitrage but a deliberate exit by a whale, possibly due to internal risk limits or market predictions. The trade's urgency and structure, including the use of Intermarket Sweep Orders, highlight the seller's focus on speed over price. Following the trade, BlackRock's IBIT experienced significant outflows, contributing to a $2.4 billion monthly decline in US-listed spot Bitcoin ETFs, as the crypto market faced a challenging month.