What it is
A UTXO, or unspent transaction output, is a record on the Bitcoin blockchain of a specific amount of bitcoin that has been received but not yet spent. When a Bitcoin transaction occurs, it consumes one or more existing UTXOs as inputs and creates new UTXOs as outputs. For example, if you receive 1 BTC, that 1 BTC exists as a UTXO. When you spend 0.5 BTC, the 1 BTC UTXO is consumed, and two new UTXOs are created: 0.5 BTC for the recipient and 0.5 BTC (minus fees) as change back to you.
UTXOs are crucial for understanding Bitcoin's accounting model, which differs from traditional bank accounts. Instead of a balance, a Bitcoin wallet's total funds are the sum of all its accessible UTXOs. On-chain analysis often uses UTXO data to track coin movements, identify long-term holders, or analyze market cycles. Metrics like "UTXO age bands" can indicate HODLing behavior or potential selling pressure when older UTXOs start moving, providing insights into investor sentiment and market trends.
Why it matters
UTXOs are the building blocks of every Bitcoin transaction. Knowing how they work provides a deeper understanding of Bitcoin's security and on-chain metrics used by analysts.
Reviewed under editorial standardsUpdated September 26, 2026Not investment advice