The Vibe: A sneaky DeFi trick where bots “sandwich” your big trade with their own buys and sells—pushing the price against you so you pay more (or get less), while they pocket the difference.
The Details: A sandwich attack is a type of MEV (maximally extractable value) exploit on decentralized exchanges (DEXs) like Uniswap or PancakeSwap. Bots scan the public mempool (pending transactions queue) for large swaps that will cause big price slippage. They then place: one buy order just before your transaction (front-running to drive up the price), let your trade go through at the worse rate, and immediately sell after (back-running) to profit from the price bump you caused. You end up with fewer tokens than expected due to extra slippage; the attacker makes risk-free profit. Common on Ethereum and other chains with public mempools—still happens in 2026, though some DEXs and private relays reduce it.
Pro Tip: Use DEXs with MEV protection (like CoW Swap, 1inch with private relays, or Flashbots Protect). Set low slippage tolerance (0.5-1%) for trades, avoid huge swaps during volatile times, and try smaller orders split over time. Check tools like MEV Blocker or private RPCs for safer swaps—always preview the expected output before confirming.