Nearly half of all bitcoin BTC$67,676.44 in circulation is now worth less than it was bought for, according to data from the Bitcoin Impact Index, which jumped sharply last week as stress returned across all segments of the market.

The index, which measures financial stress for bitcoin user cohorts based on onchain behavior, ETF and derivatives activity and liquidity flows, surged 13 points to 57.4 during the week ended March 28, its steepest climb since January, CEX.IO noted in a recent report.

That level, from a range of up to 100, lands it squarely in what’s seen as the “high impact” zone that historically signals the kinds of broad selloffs that led to double-digit price drops in 2018, 2022 and earlier this year.

Long-term holders, wallets that have held BTC for more than six months, were selling at a profit just a week ago, when the cryptocurrency was trading above $70,000. Now, over 4.6 million BTC from these wallets, or roughly 30% of their total holdings, are underwater, the report notes. Their realized losses last week were the worst since 2023.

“This kind of divergence between price action and on-chain conviction has historically been a warning sign,” the firm wrote. “For instance, similar moves occurred in mid-2018 and mid-2022 before price drops by over 25%.”

Short-term holders aren't faring any better. The report found that 47% of the total bitcoin supply is currently held at a loss, levels not seen since the market’s most stressed stretch in February.

At the same time, capital flows that had supported the market earlier this month have pulled back. Daily stablecoin net flows, which had averaged inflows of $250 million, flipped to outflows of $292 million. ETFs and miners also moved from accumulation to selling, the firm wrote.

So far, one key support remains intact: Onchain data shows holders are not rushing to deposit BTC on exchanges en masse, a behavior often seen in full capitulations.