Bank of America strategist Michael Hartnett warned that a wave of mega‑IPOs could inflate tech’s share of equity indexes to levels reminiscent of the 1920s bubble. He cited upcoming offerings from SpaceX and OpenAI as prime examples that would push benchmark weightings beyond historically sustainable concentrations. Hartnett’s alert follows a period of rapid private‑market fundraising for AI and space ventures.

Investors monitor the potential distortion because higher tech weighting can magnify index‑linked fund flows, amplify volatility, and skew valuation metrics across sectors. Should the mega‑IPOs price at premium multiples, index providers may need to rebalance, forcing large passive managers to buy or sell significant positions. The scenario raises questions about market depth and the ability of traditional investors to absorb such size.

Hartnett’s caution signals that regulators and index committees may scrutinize upcoming filings more closely, potentially prompting tighter listing standards or disclosure requirements. Market participants should assess the trade‑off between capital‑raising ambitions and the systemic risk of crowding tech in core equity benchmarks. In the short term, heightened awareness could temper pricing enthusiasm for the slated offerings among investors.