How Does the Transaction Finality of a Blockchain Affect the Risk of Double-Spending?

Transaction finality refers to the point at which a transaction is irreversible and guaranteed to be part of the permanent blockchain history. Blockchains with faster or guaranteed finality mechanisms (like many PoS chains) significantly reduce the window of opportunity for a double-spend attack.

In a PoW chain, finality is probabilistic, meaning the risk decreases with each subsequent block confirmation. The longer it takes to achieve high-probability finality, the higher the risk that an attacker can reorganize the chain and execute a double-spend.