Space X is just warming up, and will become one of the most valuable companies of all time. As for as his wealth goes, he has said in the past he would use it to fund the first colony on Mars. He has even said that he would like to die on Mars and be buried there. His vision may yet drive humans into a multiplanetary species. The future will be fascinating, if only we can live long enough to see it!

I wish I could have afforded to invest one billion in Space X stock like that woman from Australia. Just imagine having that much wealth at your fingertips...