MEV and Front-Running Protection
MEV (Maximal Extractable Value) is how your DeFi trades can be exploited by sophisticated bots.
What is MEV?
Definition
- Value extracted by manipulating transaction order
- Block builders and searchers profit
- Costs regular users money
- A hidden tax on DeFi users
Types of MEV
Front-Running- Bot sees your pending transaction
- Places trade before yours
- Profits from price impact
- You get worse execution
- Bot places trade before AND after yours
- Squeezes profit from your transaction
- Very common on Uniswap/DEXes
- Can cost 1-5% of trade value
- Bot trades right after yours
- Captures arbitrage opportunity
- Less harmful to you directly
How to Protect Yourself
Slippage Settings
- Set tight slippage tolerance (0.5-1%)
- Prevents large price impact
- Trade may fail but you save money
- Wider for volatile tokens
Private Transactions
- Flashbots Protect: Private mempool
- MEV Blocker: RPC endpoint
- Prevents front-running
- Free to use
DEX Aggregators
- 1inch: Splits across DEXes
- CowSwap: Batch auctions
- Matcha: Optimal routing
- Better execution than single DEX
Timing
- Smaller trades attract less MEV
- Split large trades into smaller ones
- Use limit orders when available
- Avoid trading during peak congestion
Checking for MEV
Tools
- EigenPhi: MEV transaction explorer
- Flashbots Dashboard: MEV statistics
- Check your transactions for sandwich attacks
Key Takeaways
- MEV is a real cost of DeFi trading
- Use MEV protection tools
- Set reasonable slippage limits
- Split large trades
- Consider private transaction services