Maximal Extractable Value (MEV) protection keeps your Ethereum DeFi transactions private until they are confirmed on the blockchain, shielding them from bots and other actors that exploit transaction ordering. Fireblocks enables MEV protection by default for all dApp and API transactions.

How MEV protection works

When you submit a DeFi transaction without protection, bots can see it in the public mempool (the queue of transactions waiting to be included in the block) before it is confirmed. This gives them an opportunity to manipulate transaction ordering and profit at your expense through attacks such as:

• Front-running: a bot detects your transaction and submits its own with a higher gas fee, so its transaction is processed first. This drives up the price you pay for the asset.
• Sandwich attacks: a bot places one transaction immediately before yours and another immediately after, buying the asset ahead of you and selling it right after to pocket the price difference.

With MEV protection enabled, Fireblocks routes your transaction through a private node instead of the public mempool. Your transaction details stay hidden from bots until the transaction is confirmed, preventing these attacks and reducing slippage.

Important considerations

• MEV protection is available for Ethereum transactions only.
• MEV protection significantly reduces the risk of front-running and sandwich attacks but does not guarantee complete protection in all cases, see more here. 
• MEV protection is available for DeFi transactions (Contract Calls) but not for operations like Transfers, which are not as exposed to MEV attacks risks.