Nearly A Third Of All Bitcoin Now Sits Behind An Exposed Public Key, Glassnode Finds
A fresh number is circulating in Bitcoin security circles, and it is bigger than most people expected: 6.26 million BTC, or 31.2% of the entire supply, already sits in addresses whose public keys are visible on-chain.
WHERE THE NUMBER COMES FROM
Glassnode co-founder Rafael Schultze-Kraft, who posts as @n3ocortex, published the figure on October 8, writing that the exposed share is up from 24.8% in early 2021 and back to levels last seen in 2016. The biggest driver is address reuse: 4.33 million BTC sits in addresses that have already spent once, which permanently reveals the public key behind them. Another 1.94 million BTC is structurally exposed through older output types, including 1.71 million BTC in legacy Pay-to-Public-Key outputs, of which roughly 1.1 million BTC is attributed to Satoshi Nakamoto, plus 222,000 BTC in Taproot outputs that reveal a key by design.
THE WARNING THAT CAME FIRST
The data landed two days after Ethereum Foundation researcher Justin Drake posted on X calling on "the blockchain industry to calmly begin planning for 'bunker mode.'" Drake's concern isn't the long-feared quantum computer. It's that AI-accelerated mathematics could break ECDSA, the signature scheme behind both Bitcoin and Ethereum, "in months, not years." His recommendation: move funds, large holders first, into addresses that have never signed a transaction, so only a hash of the public key is visible rather than the key itself. Drake was explicit that he isn't claiming the cryptography has already fallen, and said he isn't asking for a rushed migration.
EXCHANGES ARE CARRYING THE MOST RISK
Exchanges hold about 1.79 million BTC of the exposed total, which Glassnode puts at 57% of identified exchange balances, up from 55% in its prior report and 39% at the start of 2021. The spread between platforms is wide. Coinbase sits around 10% exposed. Binance is near 83%. Bitfinex and Robinhood show 100%. Fidelity, holding 375,000 BTC, is at just 2%. Grayscale sits at 49% and Revolut at 99%. Seven of the fifteen largest exchange balances Glassnode tracked are above 99% exposed.
MIGRATION, NOT PANIC
Security researcher Taylor Monahan pushed back on the urgency of Drake's framing, saying his post risked doing "more harm than what it's warning against" by pushing people toward rushed transfers and the phishing links that tend to follow. Glassnode's own data carries the same caveat: the numbers describe address hygiene, not a confirmed attack, and are not a solvency or security ranking of any exchange or custodian. The fix for an individual holder is the one Bitcoiners have repeated for over a decade and mostly ignored anyway. Stop reusing addresses, and move coins sitting behind a spent key to one that has never signed anything.
This story comes from the Simply Bitcoin Live show. Watch the full episode.
