I think he invested a lot of money, Musk is trying to save his money. But it could be something different because Elon Musk is one of the most visionary and crazy people I've seen lately. I trust his explanations.
I can't see a logical explanation on his tweets, it is all pure speculation running by Elon's speculation team. He is a crazy person and makes fun with the pumping shitcoin with useless tweets. This is not the crypto I want to buy and make money, I always prefer to trade legit, random market movements, not the hyped trades.
I agree with you, it looks like elon is just for fun, but behind elon's tweet maybe he has adopted a lot of doge and BTC at a lower price. and sell it while the price is skyrocketing. And new investors who are FOMO will buy a very high price.