_ Emotional control: one of the most difficult thing is controlling your emotions while you watch your assets fluctuates greatly, mostly if it's going down, without you pulling the plug out of fear, so i believe it's one of the key they have.
And this is everyone's worst enemy. Because if you can't control yourself emotionally, the tendency for you to miss the opportunities are high and it might even push you to sell at prices that you don't like.
You'll not consult yourself more when you're hitting it with emotions which is a terrible idea for investing and in trading too.
_Early tech exploration: They got into the industry very early which they took good advantage of, while others were guessing and still not confident about it. They bought Bitcoin at a very cheap rate when people where even afraid of spending a thousand box on it.
While many of them understands the technology that Bitcoin has brought which is the blockchain technology, there were also many of them that are just plain believers to itself without having that much exploration to the tech.
_ Long term perspective: They don't just buy, they look at it on the long run, they know when to take risk but at the same time they don't buy and sell with emotions.
I admire those early adopters that have seen already the potential of it in the long run. We're just like passerbys but then, these people really have set the expectation of many that Bitcoin by its history and cycle, is no doubt here to stay and could blow in prices in the next coming years.
_ Patience: they have the patience needed to steadily build their wealth over the long term.
Holding is a quality of patience and most of us that know and does hold have this quality. AFAIK, most of us have all of these qualities and even they say that it's quite late already in the party.
We're still early on it if you combine being long term and optimistic about Bitcoin's tech and being an asset.