if you read reports from the BIS(bank of international settlements) you will read that for a couple years now the BIS has been drafting regulations that would allow central banks to hold crypto for use of international reserve swaps. the BIS has suggested a 2% of collateral/reserves to be in instable crypto like bitcoin and a higher single digit % in stablecoins, however central banks has been lobbying for a 5% holding in instable crypto like bitcoin, where the regulation would take effect by jan 2025
https://www.bis.org/bcbs/publ/d545.htm (initial draft 2022)
The banks has the "etf" and the "etn" and they have policies. Some trades it it and offers that service And some stick to what known for having intrinsic value. It's more about values nowadays.