Balance is the figure of the account which includes all closed trades. Equity is the actual amount of funds in the account currently including all open trades. Equity is what matters.
Equity is what needs to be tracked. For example let’s use the example that the balance is $100,000
And the equity is $90,000. You transfer funds into the bot
28 days later the balance and equity are both $100,000
You had a 11% (or whatever) gain using equity
If you used balance you had a 0% gain? No, the equity is the amount of funds in the account
At the time you send funds to the bot and they are approved a snapshot of the current equity in the account is taken. Your performance is based off of this equity baseline.