If bitcoin has a high price and is expected to fall, if we estimate bitcoin prices will rise again then I suggest do not sell first because it could be bitcoin price will be more expensive. But indeed to sell bitcoin that much risk we will get ...
I sell as an when required as i am dependent on bitcoin income for my family expenses, only 20% maximum i keep for long term investment balance i convert it to fiat currency as and when i require or when i think that the price is high and do small trading and get profit.