the Bank of international settlement (BIS)
have a guideline policy for how central banks can hoard crypto in the future
https://www.bis.org/bcbs/publ/d545.pdfthe short version for those that dont like to read
coins like BTC and ETH are set into a 'group 2b'
where the BIS advised banks only have from 2025 a individual holding 2% of crypto assets vs all combined assets. which is about if combining all banks in BIS. about $3-4trillion in bitcoin/eth
now the lengthier explainer
BIS originally set a limit of just 1% of the banks combined value, which the banks then got the BIS to change to 2%(banks want to hold crypto and more then the BIS first proposed was allowable)
based on some sources. this means of the banks combined value of 180trillion(yep i was shocked too)
the banks can hoard upto ~$3.7trillion of crypto such as ethereum/btc
there are other groups for second layer tokens and other groups for stable coins with their own limits and descriptors
but the group 2b have descriptors where the "market cap" needs to be above 10billion. and market volume of over 50m a day. meaning that rules out alot of crap coins from being in the group 2b category (sorry doge. no go, no throw, no mo)