Bitcoin is the kind of asset that you don't need to worry about selling.. just continue to buy at any price for maybe 4-10 years or longer and then reassess.
Sure it is, except someone who already owns a huge portfolio and has gotten a large amount of profits can decide to sell part of their Bitcoin
Even if you own a huge portfolio of Bitcoin doesn't mean you should sell some parts of your Bitcoin because you saw some good profit on it, actually before going into investment there should be a stage or amount were you should draw a line to meet up so that no matter the amount of Bitcoin you have accumulated you will not consider yourself to be sufficient since your goal has not been met even if you are seeing a lot of profits already from the ones you accumulated, actually this kind of goal will certainly be of help to an investor so that you will not regard the little amount of Bitcoin you have accumulated to be huge amount of Bitcoin whereas you will be having a thought of selling some parts because this has been the mindset most people normally have towards there Bitcoin.
You are right to some extent because everyone has their investments targets so if an investor has met their targets I don't think it will be problematic to consider selling part of it, so far as they already own a huge portfolio I don't think selling part will affect their holdings. Bitcoin investments is for long term purposes so I believe before someone must have own a huge portfolio it would take a long interval of time and by that time the price of Bitcoin must have skyrocket to considerable level.