U.S. Bitcoin spot exchange-traded funds suffered net outflows of $2.43 billion in May — the deepest monthly withdrawal since November 2025, according to data compiled through the final week of the month. The last week alone saw $1.42 billion leave the funds, with 14 of 20 trading days in May ending in the red. BlackRock's IBIT, the largest fund by assets, took the biggest single-fund hit.
A $2.43 billion month for outflows
The final week of May ran the losing streak to seven straight negative days. Total monthly outflows of $2.43 billion marked a sharp reversal from the steady inflows that dominated early 2026. Since their 2024 launch, the funds have pulled in a cumulative $55.66 billion, with total net assets sitting at $94.17 billion — about 6.38% of Bitcoin's market cap. That cushion means the funds are still up big overall, but the May rout is the worst monthly performance in six months.
BlackRock's IBIT takes the biggest hit
BlackRock's IBIT posted net outflows of $966.42 million during the final week of May alone — nearly 68% of the week's total. That's a striking sum for a fund that had been a magnet for institutional money. No other single fund came close. The concentrated selling suggests a large holder or group of holders exited in a hurry, though the data doesn't identify counterparties.
Bitcoin holds above $74,000 despite the selling
Bitcoin traded at $74,012 at the time of reporting, up 1.07% on the day. The price resilience stands in contrast to the ETF outflow data — normally heavy fund redemptions pressure the spot price. Daily trading volume across Bitcoin markets fell 47.55% to $18.12 billion, which may explain why the sell pressure didn't translate into a bigger price drop. Thin liquidity can mask order-book impact, but it also means a sudden volume spike could swing the market hard either way.
What comes next is unclear. The monthly outflow streak could extend into June, or dip buyers could step in. The cumulative net inflows remain deep in positive territory — $55.66 billion — but May's action serves as a reminder that even the most popular ETF products can bleed money when sentiment shifts.
