Cryptohopper doesn't have a cryptocurrency blacklist feature for trading signals for users with a Hero subscription who have 'Allow all coins' enabled in their Signal config. However, there is a way to prevent receiving trading signals in your trading bot after a position has been opened for a specific cryptocurrency.

Since, as a Hero user, you can receive all trading signals for your quote currency using the 'Allow all coins' setting, it's possible to select the cryptocurrencies from which you don't want to receive trading signals under 'Selected currencies' in the 'Currencies and amounts' section of your Base config.

Then, you can create a Config pool for these currencies and set a cooldown after buy, for example, 365 days.