In-play supply (in-play BTC)
The bitcoin realistically able to change hands: mined supply minus provably lost coins, government-seized holdings, spot-ETF custody, and public-company treasuries. It is the headline number on the Galaxy Mind float tracker and the strictest practical answer to "how much bitcoin is actually left to buy."
Distinct from "circulating supply" (which counts lost and locked coins as circulating) and from exchange balances (which measure only custodial liquidity). In-play shrinks structurally: ETFs and treasuries absorb coins daily while mining issuance halves every four years.
How to read it
In-play is the strictest practical cut of supply: coins that realistically could trade. It removes the provably lost, government stashes, ETF custody, corporate treasuries, and the deep-dormant cohort that has not moved in many years. What survives is the bitcoin actually available to absorb new demand. Read it next to circulating supply to see how misleading the headline number is.
On Galaxy Mind
In-play is the liquid in the /float reservoir and the headline 'left to buy' number above it, about 6 million BTC as of mid-2026. The allocation breakdown below the instrument shows exactly which cohort holds every other coin, and the daily snapshot cron keeps a five-year history behind the trend chart.
Context
Out of roughly 19.9 million mined coins, around 14 million sit in cohorts that have not sold through entire cycles. The hump matters too: in-play ROSE through 2016 as mined coins distributed, peaked near 46% of supply, and has receded since as ETFs and treasuries absorbed it, which is why the reservoir etches its high-water mark at 2016.