Comment by throw0101c

3 hours ago

> The most recent change was the NASDAQ adopting the "fast change rule" which allows newly IPO'd companies to be listed in the index after only 15 days of trading.

Official justification, and other changes besides timeframe, e.g.:

> First, eligibility and company size. As multi‑class share structures have become more common, we now consider both listed and unlisted shares when determining eligibility and ranking. This allows the index to reflect a company's full economic size, while index weighting remains based solely on listed shares. This change affects who qualifies for inclusion, not how constituents are weighted.

* https://www.nasdaq.com/newsroom/nasdaq100-index-methodology-...

> A new method to calculate the market capitalization of companies to determine their eligibility for inclusion in the index. It involves adding listed stock and unlisted shares that are part of different share classes. Scrapping a rule that requires companies to float a minimum 10% of their shares. Companies with a low float will receive a lower weighting on the index. […]