Slippage
The gap between the price you expected and the price you got — the cost of moving size through thin liquidity.
Slippage is execution drift: your order consumes the order book (or shifts an AMM pool) as it fills, so the average price lands worse than the quote. It scales with order size and inversely with liquidity — negligible on BTC/USDT majors, brutal on microcaps where a modest buy moves price percent by percent.
Controls: limit orders cap it at zero by definition; DEXs let you set a slippage tolerance (keep it tight — generous settings invite MEV sandwich extraction); large orders split into tranches or go OTC. If a token needs 10%+ tolerance to trade at all, that itself is the risk disclosure.