defi-mev-battletest

DeFi/MEV Battle-Tested Expert Skill

MANDATORY CONSULTATION: This skill MUST be consulted for ANY DeFi bot development, MEV strategy implementation, or automated trading system. Real-world failures and lessons learned here prevent catastrophic losses.

Trigger Keywords

• arbitrage, MEV, searcher, bot, automated trading
• backtest, simulation, paper trading
• flash loan, sandwich, frontrun
• slippage, price impact, execution
• reorg, race condition, mempool
• market making, liquidity provision

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1. CRITICAL PITFALL #1: "Arbitrage is Risk-Free" MYTH

Reality: Theoretical 0% risk, practical tail risk = DEATH

Hidden Risks in "Risk-Free" Arbitrage:

❌ Execution Risk
- Transaction reverts after gas spent
- Partial fills leave you with unwanted inventory
- Contract bugs in target protocols

❌ Reorg Risk (CRITICAL)
- Your profitable tx can be uncle'd
- 1-2 block reorgs happen DAILY on Ethereum
- Your "profit" disappears, gas cost remains

❌ Gas Spike Risk
- Base fee can 10x mid-execution
- Priority fee auctions drain profits
- Failed tx still costs full gas

❌ Latency Risk
- Block already mined before your tx lands
- State changed between simulation and execution
- Other searchers front-ran you

Real Numbers:

// What you see in backtest:
const theoreticalProfit = 0.05; // 5% clean profit

// What actually happens:
const executionCosts = {
  gasOnSuccess: 0.01,      // 1% gas
  failureRate: 0.30,       // 30% of txs fail
  gasOnFailure: 0.01,      // Still pay gas
  reorgRate: 0.02,         // 2% get reorg'd
  slippageSlip: 0.005,     // 0.5% unexpected slippage
};

// Real expected value:
// 0.70 * (0.05 - 0.01) - 0.30 * 0.01 - 0.02 * 0.04 = 0.0238
// 47% of theoretical profit GONE before MEV competition

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2. CRITICAL PITFALL #2: Backtest Overconfidence

80% of bots that fail in production looked great in backtests

Why Backtests Lie: