The conventional wisdom on Wall Street holds that a surge of initial public offerings drains liquidity from existing stocks, creating a zero-sum game where new supply cannibalizes old holdings. With the largest backlog of venture-backed unicorns in history now eyeing public markets, that theory is about to face its most rigorous stress test in decades.
Fundstrat's Tom Lee, whose bullish calls have proven prescient through multiple cycles, argues the concern is overblown. His reasoning cuts against the instincts of traders who remember how 2021's IPO bonanza preceded a brutal 2022 correction: the sheer scale of global capital markets has grown faster than the pipeline of companies waiting to list.
The arithmetic of abundance
The numbers are genuinely staggering. SpaceX, OpenAI, Stripe, Databricks, and a constellation of AI-adjacent firms represent perhaps $2-3 trillion in potential market capitalization should they all reach public markets within the next 18 months. That sounds like a tidal wave until you consider that US equity markets now exceed $55 trillion in total capitalization, with daily trading volumes routinely surpassing $500 billion.
Lee's core argument is proportionality. Even a historically large IPO year—say, $400 billion in new issuance—represents less than one percent of total market value. The 401(k) contributions, sovereign wealth fund allocations, and corporate buyback programs that flow into equities each quarter dwarf any plausible IPO calendar.
Why this time might actually be different
The more interesting question is whether these companies deserve their private valuations at all. OpenAI's reported $300 billion valuation assumes dominance in a market that barely existed three years ago. Stripe's $65 billion price tag reflects payment volumes that could compress if consumer spending weakens. SpaceX trades on Elon Musk's reputation for defying skeptics, which cuts both ways.
What separates this cohort from the class of 2021 is profitability, or at least a credible path to it. Stripe generates genuine operating income. SpaceX has recurring government contracts. Even OpenAI, for all its compute-intensive losses, can point to enterprise revenue growing faster than any software company in history. The frothy SPACs and pre-revenue moonshots that defined the last IPO boom are conspicuously absent from this roster.
Our take
Lee is probably right that the S&P 500 won't crash under the weight of new supply—markets are simply too large and too liquid for that mechanical story to hold. The real risk is subtler: that investors rotate out of mature tech giants to fund the newcomers, creating a stealth correction in names like Apple and Microsoft while headline indexes remain stable. The flood is coming; the question is which boats it lifts and which it swamps.
