What Is UTXO?
A UTXO (Unspent Transaction Output) is the fundamental accounting unit in Bitcoin and similar blockchains. Unlike account-based systems (like Ethereum), Bitcoin tracks ownership through discrete, unspent transaction outputs. When you "have" 1 BTC, you actually own one or more UTXOs that sum to 1 BTC — each a distinct piece of transaction history.
How UTXO Works
When you spend Bitcoin, you consume entire UTXOs as inputs and create new UTXOs as outputs (the payment to the recipient and the "change" back to yourself). This model enables powerful on-chain analytics: each UTXO carries a timestamp (when it was created) and a value (the price at creation), allowing metrics like SOPR, realized price, and age-based supply analysis.
Why It Matters for Traders
Understanding UTXOs is foundational for on-chain analytics. UTXO age distribution reveals holder behavior (old UTXOs = conviction, new UTXOs = speculation). UTXO value distribution shows the cost basis of the supply. The UTXO model's transparency is what makes Bitcoin's on-chain data so analytically rich — every sat can be traced through its complete transaction history.