Those are short term investors not a long-term investors, a long-term investor will not sell his investment at any given time, and if he has to sell his investment due to health issues that is after using his reserve fund am sure he will be willing to start all over again because health they say is wealth.
But for those that don't have any health issues and sold their investment because of the price increase in the market are not good investors but traders, because no matter how he struggles to get the money to come back into Bitcoin investment, will still sell off their investment again when the price goes up again, these set of persons are known as perpetual traders that are always looking for opportunities to sell.
Perhaps you might have a misinterpretation of people's action, some guys who are selling or sold around $100k are not traders perhaps you might think all that because you're still a newbie here.
Some guys acquired bitcoin or bought bitcoin when it was around a thousand $1000 - $10,000 having made so much profit sold at $100k is not an act of trading, some of this guys even use the sustainable withdrawal practice to withdraw their bitcoins yet having so much left.
If you know what bitcoin really is you will discover that if it's not exchanged, transactions taking place then it's not longer a currency that Satoshi created it for rather it's just now an investment too.