What Is the Risk of a “51% Attack” and How Does a Pool’s Size Relate to It?

A 51% attack occurs when a single entity or pool controls more than 50% of a blockchain network's total hash rate. This control allows them to potentially double-spend coins, prevent new transactions from gaining confirmation, and disrupt the network's integrity.

A very large pool that approaches this threshold poses a centralization risk. While the pool operator may not initiate the attack, their control over a majority of the hash rate makes the network vulnerable.