I have the feeling that they are in but since they know is risky, they wouldn't disclose it to the public especially when they know that central banks will harm their reputation.
Sometime before the ban of bitcoin in my country, some bank workers were expelled for risking and using customers money to buy bitcoin and after the last collapse, they couldn't balance sheet the money they took for investment.
wont tending to make out some integration in terms of payment system but talking individually then we dont know that theyre accumulating silently specially to those whom do see that it could really
have the potential to make profits and not really minding about on what would others said but its just dumb that they would really be making it obvious.Everything would really be silent
in terms of accumulations even though its not proven but its likely that it is happening behind.