Before one buy, write down two numbers: where you are wrong (the stop) and how much of the wallet you accept to lose if you are wrong.
The formula
Position = (wallet × risk %) ÷ stop distance. With a 10 SOL wallet, 1% risk and a 25% stop, the position is 0.4 SOL. Wider stop, smaller position. The Singlebuy desk does this math with the live price.
Memecoin reality
Stops slip in fast markets and some tokens cannot be sold at all. Check mint and freeze authority, top holder share and liquidity first, then size smaller than the formula says.