To really find out what next that Elon musk is going to buy or acquire, we have to first study the ones he already acquired, what moves did he make before acquiring twitter and so on, this I believe that if we can solve the mystery there, we can probably be able to guess what  other big investments Elon is about to pump money into

But then, if we must be truthful to ourselves, I would simply say that, there is absolutely no way to know what Elon is about to invest in except he give a hint about it.