The US IPO market is about to get very loud. SpaceX, Anthropic, and OpenAI are all racing toward public listings in 2026, carrying combined valuations that could exceed $3.5 trillion.

The trillion-dollar lineup

SpaceX is targeting a June 12 trading debut, with its IPO priced around June 11. The company’s estimated valuation sits at approximately $1.75 trillion, and demand has reportedly exceeded available shares.

Then there’s Anthropic. The Claude-maker confidentially filed for a US IPO on June 1, fresh off a late May fundraise that pegged its post-money valuation at around $965 billion.

OpenAI has also confidentially filed for its own listing. The Sam Altman-led company was recently valued at over $850 billion. Between these three companies alone, we’re looking at roughly $3.5 trillion in potential new market capitalization hitting public markets in a compressed window.

Cerebras Systems, the AI chip company, surged approximately 68-70% on its first trading day in May 2026, signaling that investor appetite for AI-adjacent companies remains voracious.

India’s quieter debut season

India’s IPO market tells a very different story. The country’s listings this year have featured smaller offerings, including companies like Horizon Reclaim and Susan Electricals.

The most notable Indian tech listing of the year was Fractal Analytics, which went public in February 2026 as India’s first pure AI firm. It carried a valuation of roughly $1.59 billion. Fractal debuted about 3% below its issue price and closed the day down approximately 7%.

The concentration problem nobody wants to talk about

AI firms are projected to account for nearly 50% of the S&P 500’s weight once these companies go public and get added to major indices. Index fund investors would suddenly find themselves with half their portfolio exposed to AI, and every passive dollar flowing into index funds would disproportionately support these mega-cap names.

There are also legitimate questions about liquidity. The rules governing how quickly new listings get added to indices like the S&P 500 may need to be revisited entirely.

What this means for investors

The first-day pop at Cerebras is encouraging, but Fractal’s stumble is a reminder that not every AI label translates into investor enthusiasm. The difference between a 70% first-day gain and a 7% decline often comes down to perceived technological moat.

If SpaceX, Anthropic, and OpenAI all price within weeks of each other, even the deepest capital markets could experience indigestion. Investors should watch the SpaceX pricing closely as a bellwether. If demand truly exceeds supply at a $1.75 trillion valuation, it confirms that the market has enough appetite to absorb multiple mega-IPOs.