Elon Musk's fortune dropped below $700 billion for the first time since December after SpaceX shares fell 4.8% on Monday, extending their decline to nearly 50% from June's peak. The fall wiped about $29.5 billion off his wealth, reducing his net worth to $695.7 billion, months after he became world’s first trillionaire. Last week, Musk called himself a "Former trillionaire".