> From what I know in Europe, you generally have to pay tax in the place where you reside more than 50% of the year
What's the definition of "reside"? In the US, it's generally not just a matter of where you sleep at night or where you keep stuff; the legal definition of "residence" is a matter of intent, where you intend your permanent place of residence to be. Of course there needs to be objective evidence of your intent: you can't just say "I live in Texas" if you own a home in California which you aren't renting to anyone else, but don't own any real estate in Texas. But it looks like Musk is selling all his California property. Even if he doesn't buy a home in Texas, if he has a permanent rental of one there, but only rents places in California temporarily when he travels there for business, legally his residence would indeed be in Texas.
What's the definition of "reside"? In the US, it's generally not just a matter of where you sleep at night or where you keep stuff; the legal definition of "residence" is a matter of intent, where you intend your permanent place of residence to be. Of course there needs to be objective evidence of your intent: you can't just say "I live in Texas" if you own a home in California which you aren't renting to anyone else, but don't own any real estate in Texas. But it looks like Musk is selling all his California property. Even if he doesn't buy a home in Texas, if he has a permanent rental of one there, but only rents places in California temporarily when he travels there for business, legally his residence would indeed be in Texas.