More than 6 million bitcoin sit behind public keys already visible on the blockchain, representing 31.2% of circulating supply, according to data from blockchain analytics firm Glassnode. This marks an increase of roughly 5 to 6 percentage points above the 2023 low.
The exposed supply has grown by 222,000 BTC ($18.2 billion) since May, with the total bitcoin supply expanding by just 64,000 BTC during the same period. Cryptocurrency exchanges account for much of the increase, adding 123,000 BTC of exposed supply and now holding 1.79 million BTC behind visible public keys.
Exposure levels vary significantly among major institutions. Coinbase maintains an exposed share of 10%, while Binance's reaches 83%. Fidelity holds approximately 375,000 BTC with just 2% exposed, Grayscale shows 49%, Revolut 99%, and Robinhood 100%. U.S., U.K., and El Salvador government holdings show no exposure under this methodology.
How Public Keys Become Exposed
Public keys become visible through address reuse or appear directly in certain bitcoin output types, including early pay-to-public-key outputs and Taproot. A sufficiently advanced quantum computer or a significant mathematical breakthrough could theoretically allow attackers to derive the corresponding private keys from exposed public keys.
Warnings on Cryptographic Threats
The findings emerge as Ethereum researcher Justin Drake has urged the industry to prepare for potential threats to wallet cryptography. Drake warned that artificial intelligence could potentially uncover a shortcut to breaking wallet security in a much faster timeframe than previously expected. However, no practical attack on bitcoin or ether wallet keys has been demonstrated to date.
