Not helang born, unlike helang born, pipit don't have the money to fund their own company. They have to give up equity to gain fund from venture capitalist. That's why you heard often founder sold all their share after the company already big because they already loss all the control to the company giving up so many equity
The way Elon do it, start up valuable company then sell to helang venture capitalist, then start up another company sell to helang venture capitalist again. Then he become helang venture capitalist himself and buy other company (tesla) and finally have the money to keep his own company (space x)