Hi CJMy reply will be in two parts as I will have to do more...

Hi CJ

My reply will be in two parts as I will have to do more research to confirm the answer regarding selection criterion for the ASX100

This is part 1

The EPS and profitability criteria applies solely to the index named S&P/ASX Small Ordinaries Select Index which is unrelated to the ASX100.

Its selection criterion and methodology do not apply to companies entering the ASX100.

Now the ASX100 is meant to represent the market not only based on companies' market cap but also by sector.

There is an sectorial index called ASX100 (Materials) and it only includes 18 companies which are the ones that are part of the ASX100 and part of the Materials sector

https://www.spglobal.com/spdji/en/indices/equity/sp-asx-100-materials/#data

Lynas falls within the Materials sector which covers 5 industries including Metals & Mining.

So if the ASX100 only covers 18 companies in a sector that covers 5 industries, LYC might simply have been too small during the last quarter to enter the ASX100.

This is what I will have to research more about.