The data options for optimising a cBot is the same as what you use when you backtest so that the type of data that is used can be configured, rather than duplicate what we have written in the backtest section, the link below will take you to an article where it will explain the different options you have. It may be worth noting that if you optimise a trading system using tick-data it will include much more historical data as well as all the different spread values, but it may take many days to complete, we recommend that you start with m1 bars from the server first.