I am not entirely sure if he is a speculator, it is more of a feeling of narcissistic approach if you ask me. Realistically speaking we are in a situation where Elon writes anything about bitcoin or doge and there are thousands upon thousands (tens of thousands, nearly millions) people who show him love, everyone says how they love Elon and how he is a genius for buying crypto and etc etc, basically make him feel good.

Now if you are a person who likes that kind of thing, and just do things that makes people love you, have zero characteristic of your own, buy crypto if people love you, and sell crypto if that will make people love you even more, just do whatever people will love you for, that means you are narcissistic and Elon is a huge one. That is why he is doing all of this, he doesn't care about money at all, he has never cared about money once in his life.