What is a sniper bot in crypto? How launch snipers buy in the same block as the pool and what stops them

On most launches the first buy after the creator's is not a person. It is a program that saw the pool appear, checked in a few milliseconds that the coin could be sold, and sent a transaction that landed in the same block as the pool itself. That program is a sniper bot. Meme coin snipers and bots covers how to recognize one on a coin and protect yourself as a buyer; this guide goes one level down and explains how the bot actually works, step by step, because knowing the mechanism is what lets a creator design a launch that does not hand the first 20% of supply to three scripts, and lets a trader read a sniped chart correctly.

What a sniper bot is, in one paragraph

A sniper bot is an automated trader whose only edge is speed at a known moment. It does not predict which coins will do well. It knows that on a new pool the first buyer gets the lowest price by definition, and that enough human buyers arrive in the following minutes to sell into. The bot's job is to be that first buyer, on every pool it can, with a position sized so that the losers (coins that never get a second buyer) are covered by the winners. It is a volume business run against the structure of launches, not a bet on any particular coin.

Step 1: detecting the launch

Bots find launches in three ways. The first is to watch for pool-creation events: a DEX factory emits a log when a new pair is created, and a bot subscribed to that factory sees the token address within the same block. The second is to watch pending transactions: on chains with a public mempool, the transaction that adds liquidity is visible before it executes, and a bot can prepare its buy to land immediately after. The third is to watch a launchpad's own contracts or feed, which announce new coins with a known structure. On chains where the sequencer's mempool is private, such as OP Stack chains including Base, the second method is unavailable and bots fall back to the first, which still gives them a one-block lead over anyone reading a chart.

Step 2: deciding whether to buy

Before sending, a serious bot simulates the trade. It runs a buy and then a sell of the token against a local copy of the chain state and checks: does the sell succeed (not a honeypot), what fraction of the coins arrive (transfer tax), is there a maximum wallet or maximum transaction size, can the owner pause transfers or change fees, and how much liquidity is in the pool. Each check is a filter. Most bots skip tokens with any tax above a small threshold and any pool under a minimum size, because the payoff is not worth the risk. This simulation takes milliseconds and is the same category of check that a launchpad's automated safety screen runs; on sasa, every coin listed on Explore has passed a check for liquidity, taxes, owner powers and holder concentration, so the properties a bot screens for are visible to a human buyer too.

Step 3: landing first

1. The transaction is signed in advance, with the token address filled in at the last moment, so no time is spent on signing.
2. It is sent with a high priority fee, so the block builder or sequencer orders it ahead of normal traffic. On an L2 with first-come-first-served ordering, the bot instead competes on raw latency: being connected directly to the sequencer with the lowest round trip.
3. Where bundling is available, the buy is sent as a bundle that lands only if it executes in the first position after the pool creation; otherwise it is dropped and costs nothing.
4. Many bots split the buy across several wallets so that no single address shows a large first buy, which is why how to spot bundled wallets starts with same-block buys from freshly funded addresses.

Step 4: the exit

A sniper's sell is as scripted as its buy. Typical rules: sell half at two times entry, sell the rest at a time limit or a trailing stop, sell everything immediately if the creator's wallet sells or if liquidity drops. The exit is where humans meet the bot: the first wave of buyers who saw the coin on a screener or on X are the counterparty. On a chart this appears as a sharp first candle followed by a sell of similar size within minutes, and on the holder list as the first buyers' balances going to zero while the holder count is still rising. That pattern is pattern one in why most meme coins die in the first hour.

The economics: why bots keep doing it

Take a bot that snipes 100 pools in a day with $50 each, $5,000 deployed. Suppose 70 coins never attract a second wave and the bot exits at a 40% loss after fees and impact: minus $1,400. Twenty coins double and the bot sells into the wave: plus $1,000. Ten coins go five times or more before the bot's time limit: plus $2,000 or more. Net, the day is positive even with a 70% failure rate, because the bot's entry price is the lowest anyone will ever pay. The strategy breaks when any of three things change: the entry stops being the lowest price, the failure rate rises because buyers learn to avoid sniped coins, or the cost per attempt rises because of gas or minimum buys. Launch design can push on all three.

What launch designs do to snipers

• Direct pool launches: the pool exists at a known price from block one, which is the bot's ideal case. The first block often contains the creator's liquidity transaction and several sniper buys.
• Bonding curves: the coin starts on a curve contract before any DEX pool, so pool-watching bots see nothing; launchpad-watching bots still buy in the first seconds, but the curve's rising price means the second and third bots pay more than the first, which thins the field. See what is a bonding curve.
• Launch races: in sasa's model the coin opens on four chains at once with a combined starting market cap of about $3,000, and for five minutes buyers on any chain are buying into pools that will be consolidated at the Chainlink price. The pools also open with a higher fee that falls to 2% within the first few minutes, so a block-one buy costs more than a later one. A bot that snipes the Base pool in block one holds coins on a chain that may lose; the coins carry over to the winner, but the bot's edge of a few milliseconds is spread over a five-minute window in which a hundred human buyers can enter at prices that are not far from the bot's. How the 5-minute launch race works walks through the consolidation.
• Creator first buy: a required opening buy on each chain (on sasa we recommend $5 or more per chain) means the creator, not a bot, holds the lowest-price coins, and the creator's wallet is visible on-chain for buyers to judge.
• Anti-bot rules in the token itself: per-wallet maximums, trading delays or blocklists in the first blocks. These work but require owner powers in the contract, which is exactly what safety checks flag, so most reputable launchpads avoid them.

Reading a sniped coin as a trader

The useful question is not 'was this coin sniped' but 'how much do the snipers hold and have they sold'. Three snipers holding 4% of supply between them and already out is background noise; three wallets holding 25% and still in is a sell wave waiting for your buy. The coin page's first-buyer list answers both questions in a few seconds. A coin whose snipers have already exited, whose holder count kept rising through that exit and whose pool is locked has passed the hardest test a new coin faces; many of the coins that run for days look exactly like this an hour in.

Sniper bots and MEV bots are different animals

A sniper takes a position and carries risk over minutes. An MEV bot, the kind that sandwiches your swap, holds nothing across a block: it buys before you and sells after you inside the same block and its profit is capped by your slippage tolerance. The defenses differ too. Against snipers, the defense is launch design and reading the first buyers. Against MEV, the defense is a low tolerance and a private route for your transaction; the mechanics are in MEV in meme coin trading. Some operators run both, but on a coin page they leave different footprints: snipers appear in the first buyers list, sandwichers appear as paired trades around other people's swaps. The general topic of transaction ordering and extraction is covered by the Ethereum Foundation's MEV overview.