I buy mostly to trade with them. You might call that speculation. There is a fine line between the last three categories in your poll. To invest and to speculate is almost the same, and you do either of them in order to win. So in reality you are asking whether we buy to make money or for fun, and nobody is really buying for fun. The only exception would be if a billionaire wanted to throw some money to buy some cryptocurrencies just for fun, just because he can. All the others are there to make money, one way or another.