Elon Musk periodically ranks first in terms of wealth on this planet. Therefore, it makes no sense for him to make money on his tweets in cryptocurrency. Most likely, he is just interested in watching how people react to his statements on social networks. This flatters his pride and he does it half-playing, half-joking.
Since his actions generate general interest in cryptocurrency, I take them pretty positively.
Initially everyone thought Elon Musk was trolling the entire cryptocurrency market with his tweets about Dogecoin but when the news of his company invested billions in the Bitcoin market then it is a different aspect as there is no clarity regarding his Dogecoin investment when he was tweeting about it as he clearly knows that his tweets would garner attention and people will invest and if he was doing that to increase his profits then it is a really wrong concept.