A key on-chain metric for Bitcoin is flashing a signal that has preceded every major bull market since 2012. More than 71% of Bitcoin’s circulating supply is currently sitting in unrealized profit, according to Bitfinex, approaching the zone that has historically marked the transition from bearish to bullish market phases.

The numbers behind the signal

The metric, which tracks what percentage of all circulating Bitcoin was last moved at a price lower than the current spot price, has been climbing steadily throughout the summer. On August 27, Bitcoin closed at $80,256, pushing 72.1% of the supply into profit territory.

That reading didn’t stick. As prices pulled back in subsequent sessions, the figure dipped to 67.7%, illustrating just how sensitive the metric is to relatively modest price swings.

By early September, with Bitcoin trading near $77,381, the supply in profit had settled around 68%, according to data from Glassnode and CryptoQuant. That represents a meaningful improvement from roughly 65% earlier in the year.