I think Elon is trying to hype projects, to make the most out of it, pumping coins will benefit him, buying before making a statement, with Cardano I think some people in the community just make news that Elon invests with ADA, Elon never tweets Cardano, most of his tweets are just Doge and bitcoin, if you believe rumors without even making your own research there is a risk that you might lose your investment.