alt Hacker NewsApparently the rule change also affects CRSP, which is the index behind Vanguard's Total Stock Market (VTI) index funds.
https://finance.yahoo.com/markets/stocks/articles/spacex-ipo...
VTI in turn is the primary holding of most of Vanguard's Target Date retirement funds, which are widely held in 401ks.
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Recent changes:
> CRSP indexes were also recently changed to better accommodate fast entry. New IPOs are eligible for CRSP's suite of indexes after five trading days, provided they pass the index's eligibility and investability screens. Previously, these screens included having at least 10% of shares qualifying as freely tradeable (known as float shares outstanding, or FSO). However, in April the methodology changed to allow stocks with either 10% FSO or approximately $3.3 billion in float-adjusted market capitalization to be eligible for index inclusion. The weighting of stocks in CRSP indexes is also based on free float, which should help address the investability challenges associated with thinly traded stocks.
* https://www.schwab.com/learn/story/some-indexes-accelerate-e...
NASDAQ index has a 3x float weighting (and a far, far smaller total capitalization) which makes it far more susceptible.
Other indexes do not have these multipliers, and are much larger. The exposure for e.g. VTI is far, far less.