Bitcoin's chain splitting mechanism is often misunderstood as a generous airdrop of new tokens to existing holders. However, this isn't about creating value out of thin air, it's simply about duplicating recognition of an existing ownership record across two ledgers.
The key to understanding this lies in how Bitcoin tracks ownership: not through account balances or running totals, but through unspent transaction outputs (UTXOs). Each UTXO is a discrete chunk of bitcoin locked to a specific key, and the wallet balance is simply the sum of every UTXO that the private key can unlock.
When a hard fork occurs, two networks begin enforcing different rules starting from the same shared point in history. Since both chains have identical records up to that point, no new transaction or reissue is necessary, the 1:1 ratio simply reflects the duplication of existing UTXOs across two ledgers.
While this might seem like a straightforward process, there are important caveats to consider. For one thing, serious forks often implement replay protection to prevent transactions from being reused on both chains. This is particularly crucial in preventing the loss of control over forked coins by holders.
In addition, mining difficulty plays a significant role in determining the stability and usability of the new chain. A forked chain inherits Bitcoin's mining difficulty, which may not align with its actual hashrate, leading to potential issues with block production and network disruption.