U.S. spot Bitcoin ETFs just wrapped up their worst stretch on record. From May 15 through May 29, the funds bled $2.97 billion in cumulative net outflows over ten straight trading sessions — the longest such streak since the products launched. The sell-off accelerated in the final week, capped by a single-day $527.84 million redemption on May 27 from BlackRock's IBIT.
The $1.29 billion block trade and what it signals
On May 26, an off-exchange block trade of roughly 29.2 million IBIT shares — worth about $1.29 billion at the time — moved in one shot. The next day came one of IBIT's largest single-day outflows. Portfolio managers cited in the article say the sequence looks like a big institutional rotation: sell ETF shares, redeem, and move the cash into AI leaders. Not every block trade triggers a redemption; primary creations and redemptions are netted at the end of the day. But in this case the numbers line up cleanly.
The $86,900 cost-basis wall
On-chain data reveals a thick layer of investor supply clustered near $86,900 — positions built between November and February. That band of breakeven supply acts like a speed bump. When prices rally into that zone, it dampens trend strength because holders who bought around that level are motivated to sell or reduce risk. The outflow streak didn't happen in a vacuum; price action was already bumping against that zone through late May.
ETFs flip from accumulation to distribution
By late May, spot ETFs had absorbed only about 4,500 BTC year-to-date. That's a dramatic slowdown from earlier months, and the month itself had flipped into net distribution — meaning more bitcoin left the funds than entered. The streak of $2.97 billion in combined net outflows over ten days erased most of the inflows from the prior rally. The block trade and redemption were the exclamation point, not the whole story.
Whether the rotation into AI stocks continues or bitcoin finds a bid above that $86,900 supply layer is the unresolved question. The ETFs' net flow data for the first week of June will be the next concrete clue.
