SpaceX shares began trading for about $150 each, 11 per cent higher than the $135 estimate.

Traders on Polymarket think it's likely SpaceX will join a group of just six companies boasting a market value beyond $2 trillion.

Wits its official share pricing announcement, SpaceX's IPO has begun.

Musk owns 85 percent of the controlling shares, so “public” is relative.