He made most of his profits from cardano. He somehow knew that its gonna be big. That's the key to his success. He knew it before the masses know it. That's how it is.
People who can't sense these things or don't do proper research shouldn't do what he does. Buy&hold is usually better for them.
That was like this with bitcoin, was the same for eth and now cardano. Early investors took the risk and made the most buck. Now many people know that bitcoin has the minimum risk most of them buying btc, and naturally making less
P.S I would cash out my money after reaching 500k+ no need to prove anything further imho. 500k$ should be enough for an average person to retire himself.
I think this thread succeeded its target already.