Lesson 10: Flash Loans and Advanced Primitives
🎯 Core Concept: Flash Loans
Flash Loans represent a financial primitive with no equivalent in traditional finance. They allow borrowing immense capital without upfront collateral, provided the liquidity is returned within the same transaction block.
📚 How Flash Loans Work
The Mechanism:
- Borrow funds (no collateral needed)
- Execute operations (arbitrage, collateral swapping, etc.)
- Repay loan + fee in the same transaction
- If repayment fails → entire transaction reverts (as if it never happened)
Key Insight: The atomicity of blockchain transactions makes this possible. Either everything succeeds or nothing happens.
📚 Use Cases
- Arbitrage: Buy on Exchange A, sell on Exchange B
- Collateral Swapping: Refinance loans without upfront capital
- Liquidation: Liquidate positions and keep the bonus
The Dark Side: Flash loans are also used by attackers to maximize exploit impact.
Interactive Yield Farming Calculator
Use this interactive tool to calculate potential yields from advanced DeFi strategies:
🔑 Key Takeaways
- No Collateral Required: Flash loans don't require upfront capital
- Atomic Transactions: Must repay in the same block or transaction reverts
- Powerful Tool: Enables sophisticated DeFi strategies
- Also a Weapon: Attackers use flash loans to amplify exploits
- DeFi-Native: This primitive only exists in DeFi, not TradFi
Next Lesson: In Lesson 11, we'll explore comprehensive risk management in DeFi.