Elon Musk has lost over $600 billion from his peak fortune as SpaceX shares continue to slide. After the stock fell another 4.8% on Monday, his net worth dropped by about $29.5 billion to $695.7 billion, according to Forbes. Musk, who briefly became the world's first trillionaire after SpaceX's post-IPO surge, recently described himself as a “(Former) trillionaire” on X.