Warning: “Existential Risk” as Mega IPOs Could Trigger $100 Billion Stock Selloff

The article warns that a wave of mega-IPOs (notably OpenAI and SpaceX) could destabilize passive index mechanics and trigger forced selling in the S&P 500, potentially sparking up to a $100 billion stock selloff. Because S&P additions are mechanically required within 15 days of listing, passive funds would need to buy newly listed mega-cap stocks immediately, forcing sales of existing large-cap holdings to rebalance. High concentrations in NVDA, AAPL and MSFT within SPY and QQQ make them likely candidates for liquidation pressure. The piece frames the risk as structural — a liquidity/plumbing problem rather than a fundamentals issue — and highlights market stress signals (VIX spike) and the scale of potential supply from multi-hundred-billion-dollar IPOs.