What Is ‘Economic Finality’ in a Consensus Mechanism?

Economic finality refers to the point at which a transaction is considered irreversible due to the immense financial cost required to reverse it. In Proof-of-Stake (PoS) systems, this is achieved because reversing a transaction would require an attacker to spend a vast amount of capital to acquire a majority stake and then risk that stake being 'slashed' (confiscated).

The financial loss makes the reversal economically prohibitive, ensuring the transaction's finality.