The structural buyer that powered bitcoin's 2025 rally has switched sides.
U.S. spot bitcoin ETFs have absorbed a net 4,500 BTC since January 1, 2026 — a figure thin enough to signal the buying channel has essentially closed. During the same products' breakout year in 2025, cumulative inflows ran into the hundreds of thousands of coins as ETFs cleared supply from miners, long-term holders, and traders taking profit. That clearing mechanism is gone. May has actively reversed course: CryptoOnchain recorded $1.74 billion in U.S. spot ETF withdrawals over the past two weeks as of May 27, flipping the steady March-April accumulation pattern into distribution.
Swissblock, the on-chain analytics firm, published the 4,500 BTC figure on X on Tuesday and tied it directly to a shift in its Risk Index. "After strong accumulation in March and April, May has flipped back into distribution," Swissblock wrote. "The Risk Index is now moving into high-risk territory while ETF flows are deteriorating simultaneously. That tells us spot ETF demand is no longer absorbing selling pressure effectively." The Risk Index measures structural selling pressure against absorption capacity — its move into high-risk territory alongside the distribution data means neither condition is improving.
The mechanism matters. In previous bitcoin rallies this cycle, ETF buying provided a bid against miner outflows and long-term holder selling. When that bid thins, the supply has to find a new buyer or the price drops until one emerges. Bitcoin was trading at $75,808 in Asian hours Tuesday — below the $76,000 threshold that Bitmine Chairman Tom Lee said at Consensus 2026 on May 7 must hold by month-end to confirm the bear market is definitively over. BTC had briefly tested $78,000 on Monday before being rejected.
Derivatives data confirms the distribution narrative. Bitcoin open interest climbed to 740K BTC from 704K BTC while price fell 1% in the past 24 hours — a combination that typically signals a confirmed price downtrend, per CoinDesk's May 27 coverage. Ether's open interest hit a record 15.57 million ETH alongside negative cumulative volume delta, indicating traders are actively shorting rather than hedging long exposure. Crypto futures volume spiked 54% to $201 billion in 24 hours as liquidations surged 87%, though CoinDesk noted the jump partly reflects markets reopening after an extended U.S. holiday period.
Apparent demand — which measures how much bitcoin the market absorbs relative to new supply — had already slid to its weakest reading since December before Tuesday's ETF data landed, per CoinDesk's May 26 report.
There is a counterpoint. U.S. equity markets continued higher, with S&P 500 and Nasdaq 100 futures hitting record highs Wednesday — a widening divergence from crypto's trajectory. FXPro's Alex Kuptsikevich noted that bitcoin's 50-day and 200-day moving averages are on track for a golden cross in coming weeks, a technical setup that has historically preceded rallies. ETF demand has also paused during this cycle before without triggering deeper drawdowns.
But the structural case depends on the channel that brought new institutional money in. If U.S. spot ETFs remain in net distribution with three days left in May, the market is heading into June without the clearing mechanism that defined the previous advance — and below the price level Tom Lee set as the line between bull and bear.
Sources: CoinDesk (ETF demand, May 27) · CoinDesk (markets overview, May 27) · CoinDesk (Tom Lee $76K, May 7) · Swissblock (@SwissblockTech)