Bitcoin's price slid to an intraday low near $72,600 on May 27, as the 30-day cost basis for recent buyers—clustered around $78,200–$78,300—flipped from support to a stubborn resistance level. The move came amid a stretch of heavy outflows from U.S. spot Bitcoin ETFs, which recorded roughly $2.26 billion in net withdrawals over the two weeks leading into late May.
Cost basis flips the script
The cost basis for traders who bought Bitcoin in the last 30 days is basically their breakeven. For weeks that level acted as a floor. Once the price broke below it, it turned into a ceiling. Every bounce toward that zone met selling pressure from holders trying to get out flat. The market didn't reclaim it, and the slide accelerated.
Options gamma amplifies the downside
Add options mechanics to the mix. Over $8 billion of negative gamma concentrated around $75k into the May 2026 options expiry. Negative gamma means dealers have to sell as the market drops, which pushes prices lower still. That dynamic helped turn a routine dip into a sharper move. The expiry has passed, but the positioning left a mark.
ETF outflows and profit-taking
U.S. spot Bitcoin ETFs bled about $2.26 billion over the two weeks through late May. That's a clear signal institutional demand took a breather. Meanwhile, the Realized Profit/Loss Ratio climbed from around 0.4 in February to about 1.8 during the rally. Translation: profit-taking was running well ahead of new spot demand. When the buyers step away, the sellers take over.
Volatility compression unwinds
30-day realized volatility sat near 27%—low by crypto standards. Low vol often encourages hedging, which can build up positioning that then snaps. As volatility expands from a compressed level, the unwind hits hard. That's part of what we saw this week.
The question now is whether buyers step in near the $72k area or if the market needs to find a new level to attract demand. The cost basis overhead won't vanish overnight, and the gamma effect hasn't fully cleared as positions roll into June.
