Well he was on Jan 7th I know its an everchanging thing.Elon Musk isn’t the richest man in the world. And what’s the significance of that tweet?
That first is a Bitcoin transaction on the block chain. In it there was an encrypted message that he also posted on his Twitter. He also added #Bitcoin to his bio.
Basically saying that Bitcoin was always inevitable because the financial system is corrupt in a way that is impossible with Bitcoin.