I don't agree to your assertion that it's not ideal to take off profits within the bull run like what's the essence of investing? Isn't it to make profits? So in a situation whereby an investor have achieved his major aim of investing which is to make profits so after selling off his bitcoins the next for him to do is to pause investing for sometime until the price begins to dip then he can start buying and holdling again till he aquires a reasonable amount or better still he apply the DCA till the price skyrockets again so that's what an experienced investor does.
You may have gotten alot of response on this but I will make some point clear to you, though the goal for some people on getting involved with Bitcoin might be for profit making but it is not ideal to sell off one's Bitcoin during the bull run as sim_card have said.
To buttress selling Bitcoin during bull run may not be a bad idea only if you have accumulated enough bitcoin, if you have enough bitcoin in your portfolio and you decide to buy on dips and sell during bull run it is more ideal so create a specific portfolio aside your original holding for the so called purpose of selling on bull run. for example if you DCA with a minimum of $50 monthly or weekly you can make and extra portfolio where you can buy on dips and sell during bull season with another $50 dollars that at any cost wouldn't affect you if lost in the process to buy as you have asserted but it will be completely wrong if you don't have a good portfolio and you practice the gambling of Bitcoin (buying on dips and selling when it skyrockets).
On this same vain it can't be advisable for any one to practice the method which you are suggesting that anyone should pause buying of Bitcoin if after selling and the market keep appreciating because of preventing loses, that is why it is always advisable to practice the DCA method that wait for a time which may probably come or may not come for you to buy again in the dips. Time waist for nobody that is the most reason why DCA is practically the best method because it prepares you for but the uppity or the dips at the same time.
In trading, making profits is not guaranteed all the time so accumulating for a very long period like 10 years as you stated may not really be an obtainable idea as the future is unpredictable no one knows how the fate of the coin might turn out due to some uncertainty that surrounds the stock coin market. Making accumulation for a very long period of time might even lead to losses because in the quest of hoping that the price will skyrocket then it suddenly starts dipping so it's really not ideal to accumulate for too long as no one can speculate or predict what it's future holds.
I might understand your point but I put it to you (Richbased) that you are completely wrong. Trading is a 50-50 game and/or gambling that is never advisable to anyone expect you are so good at it as a professional trader even as that it's still not advisable, you do not have a solid claim for disputing the fact that long term holding is not good.
Bitcoin as predicted has not reached it speculated price and as such you may be lucky enough to be among those who will be favoured with the uppity of the Bitcoin price as a result of long term holding. There is more chance of profiting with long-term holding that short term, infact a 99.99 chance of success for long term holding because after accumulating Bitcoin you will be prepared for but the upward movement of Bitcoin price and the dips at the same time. when you have a good portfolio or have accumulated enough bitcoin you cannot be affected by the price of Bitcoin at anytime because for sure Bitcoin can't go less than it has gone before and it has a guarantee that it will bounce back to a good price at any give time.