${ethereumAddress}${subaccountNonce} where the ethereumAddress is the hex version of the bech32 Injective address and the subaccountNonce is the nonce represented in 12 bytes. An example trading account at nonce 1 would be 0xc7dca7c15c364865f77a4fb67ab11dc95502e6fe000000000000000000000001.
Starting the v1.10.0 chain upgrade, the Bank balance and the default trading account (at nonce = 0) will be merged and the Bank funds will be directly used when executing trades originating from the default trading account.