Unspent Transaction Outputs (UTXOs) are cryptoasset balances that have been received by the output addresses listed in a transaction. As transactions are comprised of senders (input addresses) and receivers (output addresses), only the owner of output addresses can spend them after the transaction confirms. Said differently, UTXOs are balances received that have not yet been spent by their owners. Collectively, the UTXO set constitutes the current ownership state of a cryptonetwork. Bitcoin is the first and most predominant network that uses this structure, but there are several other UTXO-based chains.