Some people make the mistake of selling all there Bitcoin just because they want to start a new business or investment with the money and after selling it and the start there new business or investment some time later it crashes and they lose it and also lose their bitcoin investment so keep your Bitcoin investment going while trying out other business or investment.
Selling our holdings at once is never a good practice, I'm sure that Majority of this people that like selling all there bitcoin are those Investors that have not accumulate enough stash of bitcoin in thier portfolio they feel that after selling it that it won't take long to accumulate it back. While those Investors that have been struggling to reach the status of overaccumulation can only sell 5 to 10% of thier holdings whenever it double and after that will have to allow it to compound upon itself before attempting to sell again, because they know how Long it takes before they were able to reach the status of overaccumulation so they wouldn't want a situation where they will start the accumulation process all over again.
Those that are selling out their bitcoin when they have not gotten any were in their accumulation process can not be called investors but traders. Buying and selling of bitcoin are the practice of traders and you are sounding as one of them here, as an investor who has not gotten to their accumulation stage or who just started buying bitcoin shouldn't think of selling their bitcoin instead they should keep buying and holding until they have gotten to their target this should be their only focus, and sell little and still keep buying and hodl when they have gotten to their over accumulation stage .