It is very difficult for me to imagine such investors who have hold Bitcoin for 13 years. Who are these people who resisted the temptation to sell their coins when the price increased by tens of thousands of percent? I would never become one of them, since I can't hold my coins so tightly.
Don't be surprised there are people like that guess you've never met them before but I have. Since most of them are potential holders some of them who still have their Bitcoin intact for a long period are people who discover about their portfolio late.
Can you name one, a holder from 2011? Just like mentioned its hard to resist temptation of those users who held for such long where there are so many times they should sell their holdings instead since no matter what the price is they are still in thousands of profit by now.
These categories of investors are investors with a high degree of patient, and are people that understand Bitcoin fundamentals very well, and they get the sense of what Bitcoin is going to be in the future. Secondly, These could be investors that have a lot of money and luckily for them, they were able to purchase Bitcoin at a very cheap prices and saw no reason to sell but rather keep it as their retirement savings, there must be a clear reason for those people who kept theirs until now. There is this Bitcoin enthusiast I follow on Twitter who bought Bitcoin when it was just a dollar and, according to him, his aiming a $500,000 price per Bitcoin.