Anti-whale
In short Anti-whale rules are token contract limits, like a max wallet or max transaction size, meant to stop single buyers from holding or dumping too much.
Anti-whale refers to rules built into a token's contract that limit how much any one wallet can buy, sell, or hold. The idea is to stop a single large holder, a whale, from scooping up supply at launch or crashing the price with one huge sell.
The usual mechanisms are a max transaction amount, which rejects any transfer above a set number of tokens, and a max wallet amount, which blocks transfers that would push a wallet's balance over a cap, often 1 or 2 percent of supply. Some contracts add cooldowns between trades or sell taxes that rise with size. The liquidity pool, the owner, and certain addresses are normally excluded so the token can still trade and be managed.
For buyers, anti-whale limits can make a launch fairer and slow down sniper bots, since nobody can grab a huge share in one block. They are also a common source of confusion: a buy fails because it exceeds the max, or a holder cannot sell a large bag in one go and has to split it up. Bots and organized groups often get around limits by spreading purchases across many wallets.
The trap is who controls the settings. If the owner can change the limits at any time, a max transaction can be lowered to almost zero, which effectively stops everyone from selling while the excluded owner wallet trades freely. Read the contract for setter functions and see which addresses are exempt. Limits that are fixed in code, or that the owner can only raise or remove, are much less risky than ones the owner can tighten at will.