New Delhi, Dec. 17 -- Elon Musk has long held the title of the world's richest person, barring a few instances where leaders such as Oracle's Larry Ellison briefly surpassed him. Those cases appear unlikely to recur anytime soon, as the tech CEO's net worth surged to a meteoric $600 billion on Monday, driven by speculation over a SpaceX IPO.

According to Forbes Real-Time Billionaires, Musk's net worth has now exceeded $684 billion, making him the first person globally to reach that figure, amid reports that his SpaceX startup could go public at a valuation of $800 billion.

Musk added a stunning $168 billion to his wealth in a single day on Monday, followed by a further $8 billion on Tuesday, bringing his net worth to $684.2 billion.

El...