SpaceX's record-breaking IPO has made Elon Musk the world's first trillionaire, but it's set up so ordinary investors could end up holding the losses.

• SpaceX is now valued at over $2 trillion, even though it lost about $5 billion last year, mostly on hype.
• Musk keeps near-total control with super-voting shares, so public investors get no real say.
• The deal dumps an unusually large 30% of shares on small buyers, whose 401(k)s and index funds absorb them at peak prices.
• Insiders bought in cheap early and can sell later, leaving everyday retirement accounts as the "exit liquidity" when it falls.
• Musk pays the same into Social Security as someone earning $148,000, fueling calls for a wealth tax.

Outlook: If the inflated valuation collapses, the pain spreads beyond Musk's fans to regular people's retirement savings.