There's no way they can know unless if you told them when they start asking you what you spent your money on every time you made a new out going transaction.
When making a transfer, the reason for the transaction should never say anything about crypto if you bank's policy is against crypto. Use other reasons like bills, purchases etc
Banks don't know what your transfers are for if they simply base on the details of transfers you self-type in and submit your request to them. It is safe if you only write some fake reasons for your transfers.When making a transfer, the reason for the transaction should never say anything about crypto if you bank's policy is against crypto. Use other reasons like bills, purchases etc
However, to get 100% safety, for your account and money in bank account, you must contact them for details about policies with cryptocurrency trades. If they say no, you can use secret transfer details with a reminder that there will be risks of troubles. If banks detect something from your trade partners, such as money laundering or lawsuits from police, they can trace money flow from that guy to you and others. Even they won't have details that your trades are for cryptocurrencies, your fiat money for trades with those guys can be frozen, and refunded to victims or taken by governments, police.
When I do my P2P trades, I do multiple trades with not big value, and with different trade partners. Decentralize my trades can help me to reduce risks from trade partners.
