Greed is definitely the number one thing. They can invest sums that we can lose, but some of us invest amounts that are too big out of greed that they can't even afford to risk it. Greed is what continues to confuse other people, and eventually they still wonder why they have fallen for it. Imagine holding your money and then waiting until the price goes up, and all of a sudden the price begins to go up and you start buying lots of coins because you think the price is going to go up forever and you're going to become a millionaire overnight, haha, that's greed, you're taking those who've been holding a fool for a long time.