How Does a Higher Gas Fee Ensure a Transaction Is Executed First by a Validator?

On many Proof-of-Work (PoW) and Proof-of-Stake (PoS) blockchains, the block producer (miner or validator) prioritizes transactions with the highest transaction fees (gas fees). The higher fee acts as a direct incentive for the validator to include that transaction first in the next block.

A front-running bot exploits this mechanism by paying a fee slightly higher than the victim's transaction, ensuring their preemptive trade is executed first and they profit from the subsequent price movement.