Elon Musk's SpaceX is eyeing the world's biggest Initial Public Offering with a US$75 billion capital raise. Photo / Getty Images

Investors are increasingly focused on what is set to be the largest Initial Public Offering in history.

SpaceX is preparing to list on the Nasdaq this Friday at a valuation approaching US$1.8 trillion (3.1t), while seeking to raise around US$75 billion from investors. If successful, it would shatter the existing

The sheer scale of the proposed valuation is remarkable. By some estimates, initial investors will be paying around 100 times annual revenue for a company that reportedly lost close to US$5b last year.

By any traditional measure, that valuation is eye-wateringly expensive – quite literally off the planet.