The Bitcoin network has recently crossed the 18.5 million mark in terms of coins minted into circulation. However, the actual usable supply is significantly influenced by various factors such as large holders, lost coins, dormant "zombie coins," and coins held in custody. A massive visualization published by Blockchaincenter.net offers a unique perspective on the distribution of Bitcoin’s circulating supply, underscoring the digital asset’s inherent scarcity.
Circulating Supply and Exchange Holdings
As of October 2020, the outstanding circulating supply stood at approximately 18,508,600 BTC. According to the graphic, exchanges collectively hold about 2.6 million BTC, accounting for 12% of the 21 million cap. These coins are readily tradable and constitute a major portion of market liquidity. Meanwhile, roughly 328,000 BTC are mined annually until the next halving. The chart also estimates 1.5 million BTC as "zombie coins" or dormant coins that have not moved for an extended period, likely lost or forgotten.
Institutional and Special Entity Holdings
Grayscale Investments Bitcoin Trust holds 450,000 BTC, representing 2.5% of the circulating supply. Microstrategy holds 38,250 BTC, while coins locked on Ethereum (e.g., Wrapped Bitcoin) amount to 120,000 BTC. Tim Draper still holds 30,000 BTC from the early Silk Road auction. These holdings reflect Bitcoin’s growing adoption as a store of value among institutions and high-net-worth individuals.
Coins Lost, Stolen, and Tied Up in Scams
The visualization also highlights historical incidents that rendered coins effectively unavailable: the 2016 Bitfinex hack (120,000 BTC), the Plustoken scam (200,000 BTC), and the Mt. Gox wallet (166,000 BTC). These coins, while existing on the blockchain, are frozen due to legal proceedings, lost private keys, or fraud investigations, further reducing the real circulating supply.
Scarcity Outlook: Only 2.5 Million Left to Mine
Only 2.5 million BTC remain to be mined, with the last block expected around the year 2140. The network’s mining difficulty has reached 19.22T, with a hashrate of approximately 140 EH/s, underscoring its security. The next block reward halving is scheduled around May 7, 2024, which will reduce the block reward from 6.25 BTC to 3.125 BTC, further slowing the supply growth. Blockchaincenter’s visualization vividly demonstrates how Bitcoin’s supply design creates a unique scarcity, reminding the market that the actual usable supply is far less than the nominal total.