Bitcoin address reuse leaves 4.33M BTC with exposed public keys

A growing slice of Bitcoin is sitting out in the open. According to on-chain analysis from Glassnode, the balance held in reused Bitcoin addresses has climbed to 4.33 million BTC, roughly 21.5% of circulating supply.

That figure is up 14% recently. Bitcoin was designed to let people spin up a fresh address for every transaction, but a lot of holders keep going back to the same one.

Analysis shared by Glassnode analyst Rafael (@n3ocortex) puts reuse at the center of a broader exposure problem. When you combine reuse with older and structural address types, the total amount of BTC behind visible public keys reaches 6.26 million BTC, or 31.2% of total supply.

Where the exposure comes from

When you spend from an address, the transaction reveals the public key behind it. Use that address again afterward, and the coins sitting there now have their public key permanently visible on the blockchain.

Glassnode’s breakdown splits the exposure into two buckets. The larger bucket is operational, meaning behavior: people and businesses reusing addresses. That accounts for the 4.33 million BTC.

The second bucket is structural. These coins are exposed not because of anyone’s habits, but because of how certain script types work by design. Structural exposure adds another 1.94 million BTC.

Inside that structural pile, legacy Pay-to-Public-Key (P2PK) outputs hold 1.71 million BTC. P2PK is one of the oldest formats on the network, and it puts the public key directly on-chain from the start.

Of those P2PK coins, approximately 1.10 million BTC are linked to Satoshi Nakamoto, Bitcoin’s pseudonymous creator.

The remaining structural exposure comes from Taproot, which holds 222,000 BTC under visible keys.

A level not seen since around 2016

Per the research, the overall share of supply behind visible public keys has reached a level not seen since around 2016.

In early 2021, that share sat at 24.8%. It now stands at 31.2%.

Exchanges play a big role in the story. Glassnode’s data shows exchanges hold about 1.79 million BTC under visible keys.

Exposure rates vary wildly by platform. Coinbase sits at around 10%, Binance at roughly 83%, and Bitfinex at 100%.

The analysis was published on October 8, 2026. It followed discussions the previous day, October 7, about large-scale migration strategies aimed at improving address security.

What this means for holders and exchanges

For individual holders, coins held in addresses that have never been spent from keep their public keys hidden, while coins in reused addresses do not. Most modern wallets generate new receiving addresses automatically, so much of the reuse problem likely comes down to manual habits or custodial setups.

With about 1.79 million BTC on exchanges sitting under visible keys, the research flags that risks around cyberattacks and regulatory attention may increase. The research also notes that users may reassess storage practices as a result, potentially moving assets into cold storage or other setups with better address discipline.

Migrating huge reserves to fresh addresses is not as simple as clicking a button, and doing it at scale means planning, testing, and on-chain fees. That is precisely why the October 7 discussions focused on large-scale migration strategies.

Roughly 1.10 million BTC tied to Bitcoin’s creator sits in P2PK outputs that cannot be migrated unless whoever controls those keys chooses to move them.

Exposure has climbed from 24.8% to 31.2% since early 2021, and with a 14% jump in reuse-linked balances, the direction of travel is obvious. Bitcoin offers fresh addresses for free, and a growing share of supply is still choosing not to use them.