"Slippage tolerance in DeFi. What setting 0.5% actually means and when you should change it."
Slippage tolerance is one of those settings everyone uses but few people think carefully about. Here's what it actually means:
What it is: The maximum acceptable deviation from the quoted rate you're willing to accept for a transaction to execute. If you set 0.5%, you're saying "execute this trade as long as I receive at least 99.5% of the quoted amount."
What happens if slippage exceeds your tolerance: Transaction reverts. You don't execute. You get your gas back minus the gas cost.
When high slippage tolerance helps: Completing a transaction in volatile markets or on thin liquidity routes.
When high slippage tolerance hurts: It creates a wider window for MEV bots. If you'll accept up to 2% worse than quoted, bots can extract up to 2% without your transaction reverting.
The optimal setting: As low as possible while still completing the transaction. For liquid pairs on good routes, 0.3-0.5% is usually sufficient. For exotic pairs or large transactions, you may need 1-2%.
The reason this matters less on platforms with private routing (like RocketX): if bots can't see your transaction in the mempool, they can't calibrate their extraction to your slippage tolerance. The quoted rate is what you get regardless of your slippage setting.
Default slippage on most interfaces is 0.5%. That's usually fine, but understanding what it means helps you know when to adjust it.