Overview
- Glassnode's dataset, published May 20, 2026, found about 6.04 million BTC—30.2% of issued supply—sits with public keys visible on the blockchain.
- The exposed supply splits into 1.92 million BTC of structural exposure tied to address types that reveal keys by design and 4.12 million BTC of operational exposure caused by address reuse and spending behavior.
- Exchange-held balances account for roughly 1.66 million BTC within the operational bucket, and labeled custody totals vary widely with Coinbase at about 5% exposed, Binance about 85%, and Bitfinex about 100%, while several sovereign treasuries show 0% exposure.
- Glassnode and reporters stress this is not an immediate insolvency signal because many exposures are operational and can be reduced by avoiding address reuse, rotating change outputs, migrating funds, and improving key-management practices.
- If quantum computing reaches the necessary power, coins with visible public keys—including some early, likely lost Satoshi-era outputs—would be vulnerable, a reality that could push exchanges to change custody practices and revive discussions about post-quantum upgrades to Bitcoin's protocol.