These rich bitcoin holders are probably just holding their coins hoping to be richer in the future when the price increases. To say the truth 1 million of dollars is nothing nowadays to have a real rich life.
To live well they need to continue holding until bitcoin increases more its price and making investments meanwhile.
There are some people will become rich by because of holding thier bitcoin for a long period of time and i think those people are waiting to the price of bitcoin will become higher. Holding bitcoin is possible way to get rich one person, it is portant that the price is so high. For me, I'm try to hold my bitcoin for a long period of time, and i will try to do trading some of my bitcoin and i think in trading it is one that can help me to become success in life. In my life, i will try to continue to invest bitcoin, and with all of my efforts im just make all things to become successful, abd i was believing on bitcoin that soon it will help me to become rich.