A volatile stretch for SpaceX stockFriday's rally followed a rough week for SpaceX shares. Since then, Musk's wealth has swung sharply in both directions as SpaceX shares have moved. His fortune dipped below $900 billion in mid-July as shares slid toward the company's initial public offering price. As of late July, he ranked well ahead of Google co-founders Larry Page, whose net worth stood at roughly $290.1 billion, and Sergey Brin, at approximately $267.6 billion. Given how fast this figure moves day to day, it's worth checking Forbes' live tracker for the most current number before publishing.