What Is MEV? How Sandwich Attacks Quietly Tax Your Trades

You buy a token. The price you saw was fine. The price you got was worse — noticeably worse, more than slippage should explain. You shrug and blame the volatility.

Often, you were sandwiched. And once you know what that is, you'll see it everywhere.

What MEV actually is

MEV stands for Maximal Extractable Value. The plain-English version: on a public blockchain, transactions sit in a waiting area before they're confirmed, and anyone can see them. That visibility is the whole problem. Bots watch that waiting area, spot profitable trades before they execute, and reorder or insert their own transactions around yours to skim the difference.

It's not a hack. Nothing is broken. It's a structural feature of how public chains work — your pending trade is public information, and there's money in acting on it a fraction of a second before you do.

For most traders, MEV shows up as one specific thing: the sandwich.

How a sandwich attack works

A sandwich has three layers, and you're the filling.

You submit a buy for a token on thin liquidity. A bot sees it waiting. Before your transaction confirms, it does three things in sequence:

First, it buys the same token right before you — pushing the price up. Then your order executes, at that now-higher price. Then, immediately after, the bot sells the tokens it just bought, into the demand your trade created, pocketing the difference.

You paid more than you should have. The bot captured the gap. Your transaction succeeded, the chart looks normal, and nothing announces that it happened. That's why it's invisible — there's no error, no failed trade, just a slightly worse fill you have no easy way to question.

Why memecoin traders get hit hardest

Two things make a trade attractive to sandwich bots: thin liquidity and high slippage tolerance. Memecoin trading is both, by nature.

Thin liquidity means your buy moves the price more, which means there's more room for a bot to profit from moving it first. And here's the part most people get wrong: your slippage setting is an instruction to the bot. When you set slippage to 30% or 40% to make sure a snipe fills, you're telling the network you'll accept a price up to 30–40% worse. A sandwich bot reads that as permission — it can push the price almost that far and you'll still fill. High slippage doesn't just risk a bad fill; it advertises exactly how much you're willing to lose.

So the two habits that feel like they're helping you ape faster — trading thin new pools and cranking slippage — are the two that make you the most profitable target on the chain.

How to reduce your exposure

You can't delete MEV. It's baked into public chains. But you can make yourself a much worse target:

Use MEV protection. The general idea is to route your transaction so it isn't sitting in the public waiting area for bots to read — typically through private channels that skip the open mempool. When the bot can't see your trade coming, it can't sandwich it. In the Axxel bot this is a setting that is on by default; leave it on, especially on thin tokens.

Set slippage as tight as the trade allows. Not zero — a too-low setting fails on fast-moving tokens. But don't leave it at some huge blanket number out of laziness. Match it to the token's liquidity. A tighter setting caps how much a bot can extract even if it does get to you.

Be aware of pool depth. The thinner the liquidity relative to your trade size, the juicier you are. Bigger buys into shallow pools are the classic sandwich target. Splitting a large order can help, though it costs more in fees, so it's a judgement call.

Don't confuse slippage with the sandwich. Some of your bad fill is normal slippage — the price genuinely moving between when you clicked and when it executed. Some is extraction. Protection addresses the second; a sensible slippage setting limits both.

The honest bottom line

MEV is one of those things the space mostly doesn't explain to newcomers, because the people extracting it would rather you didn't notice. It's not the biggest cost in trading — fees and bad entries lose you more — but it's the most avoidable one, and it compounds quietly across every trade you make.

The fix is unglamorous: protection on, slippage sensible, awareness of what your settings are actually telling the network. Do that and you stop being the easy filling in someone else's sandwich.

Axxel includes MEV protection as a trade setting across Ethereum, Base, BSC and Solana, alongside configurable slippage — flat 0.9% per trade, non-custodial, no subscription. You can set it up in the bot in a couple of minutes.

If you want to learn more about sniping and buying tokens safely, check out our Snipe Guide.

Crypto trading carries risk. Nothing here is financial advice. Axxel is not available in all regions.