Shares in new trillionaire Elon Musk's SpaceX jumped as much as 30 percent on their trading debut.

SpaceX prices the largest IPO in history at $135 per share, targeting a $75 billion raise and a $1.8 trillion valuation as Musk nears trillionaire status.

The rockets-to-AI group priced its 555.6 million shares at $US135 a piece, one day ahead of the highly anticipated Wall Street debut.