Source

HN discussion of the Economist "Giga-IPOs" piece. Mostly corroborates the article, but adds one genuinely useful mechanism refinement (ETF-vs-pension discretion) and independently confirms the FTSE Russell 5-day fast-track.

Methodology (augstein): S&P waived the 12-month-trading + four-quarter GAAP profitability requirements (in place since 2002); Nasdaq cut seasoning 90 → 15 trading days; FTSE Russell cut to 5 days (second independent confirmation after the Economist). Recurring (low-trust, unattributed) estimate: "$30trn passive 401k"; S&P funds absorb ~19% of SpaceX float within 6 months; Russell 1000 / NDX absorb ~24%. Also: a Hedgeye X post cited as the rule-change announcement (x.com/Hedgeye/status/2060435253928604065) — source pointer, not yet verified.

Float-weight math (petesergeant / andruby / HWR_14): S&P 500 ~0.08–0.12%; NASDAQ-100 ~0.47–0.70% (3× free-float weighting up to 100%); Russell 1000 ~0.1% — matches the Economist and Friedman.

Mechanism refinement (the useful part): "forced buying" is not uniform.

• ETF index trackers have no discretion — they must hold to match the index (Arn_Thor; HWR_14).
• But pension operators are typically NOT passive (HWR_14), and large managers won't rebalance instantly because they know they'd move the market (bluGill) — they need only match returns, not holdings tick-for-tick. → So the truly forced pool is ETF index-tr...