How and on the basis of which you determine a 'ceiling rate'

In preparation, you look at the current price and the historical price development of the crypto coin in question.

If YOUR expectation is or you feel that the price of Bitcoin above € X, for example, is a one-off peak, then you do not want the trader to buy back positions if the price rises to that level. You then specify a price ceiling of 3% below as the price ceiling. If your return is now set lower than 3%, the trader will always sell his last buy at such a peak price and you have maximum return. That is the theory behind the ceiling price.