Bitcoin is increasingly being exposed in broad daylight. According to on-chain analysis by Glassnode, the balance held in reused Bitcoin addresses has climbed to 4.33 million BTC, accounting for approximately 21.5% of the circulating supply.
This figure has recently risen by 14%. Bitcoin was designed to have users generate a new address for every transaction, but a large number of holders are still repeatedly using the same address.
The analysis shared by Glassnode analyst Rafael (@n3ocortex) places address reuse at the core of a broader exposure problem. When address reuse is combined with old address types and structural address types, the total amount of BTC with visible public keys reaches 6.26 million coins, accounting for 31.2% of the total supply.
When a user initiates a spend from an address, the transaction exposes the public key behind it. After that address is used again, the Bitcoin public key within it becomes permanently visible on the blockchain.
Glassnode splits exposure into two categories. The larger category is operational behavioral exposure, namely address reuse by individuals and businesses, corresponding to 4.33 million BTC. The second category is structural exposure; these coins are exposed not because of anyone's habits, but because of the design of specific script types. Structural exposure accounts for another 1.94 million BTC.
Within structural exposure, legacy Pay-to-Public-Key (P2PK) outputs hold 1.71 million BTC. P2PK is one of the oldest formats on the Bitcoin network, writing the public key directly on-chain from the very beginning. About 1.1 million BTC of that is associated with Bitcoin's pseudonymous founder Satoshi Nakamoto.
The remaining structural exposure comes from Taproot, which holds 222,000 BTC under visible public keys.
The research shows that the share of supply with visible public keys has reached a level not seen since about 2016. In early 2021, that proportion was 24.8%, and it has now risen to 31.2%.
Exchanges play an important role in this. Glassnode data shows that exchanges hold about 1.79 million BTC under visible public keys. Exposure rates vary greatly across platforms: Coinbase is about 10%, Binance is about 83%, and Bitfinex is as high as 100%.
The analysis was published on October 8, 2026. The day before (October 7), the industry had discussed large-scale migration strategies aimed at improving address security.
For individual holders, Bitcoin stored in addresses that have never been spent still has its public key hidden; Bitcoin stored in reused addresses does not. Most modern wallets automatically generate new receiving addresses, so the reuse problem most likely comes mainly from manual operating habits or custodial arrangements.
Given that exchanges have about 1.79 million BTC under visible public keys, the research points out that risks related to cyberattacks and regulatory attention may rise. The research also mentions that users may therefore reassess their storage methods, or move assets to cold wallets or other solutions with more standardized address management.
Migrating huge reserves to entirely new addresses is not a one-click operation; large-scale migration means planning, testing, and on-chain fees. This is precisely why the related discussion on October 7 focused on large-scale migration strategies.
About 1.1 million BTC related to Bitcoin's founder are located in P2PK outputs and cannot be migrated unless the person who holds those private keys actively moves them.
Since early 2021, the exposure ratio has risen from 24.8% to 31.2%. Combined with the 14% increase in balances related to reuse, the direction of the trend is already very clear. Bitcoin can provide new addresses for free, but an ever-larger share of the supply still chooses not to use them.
