All TradeStation strategies generate entry and exit orders based on certain criteria or conditions. By default, these conditions and criteria are evaluated once per bar, at the close of the bar. If the conditions and criteria are met, orders are generated to be executed during the following bar if the price stipulations are met (i.e. limits and stops).
When automating or monitoring a strategy with real-time data, Intrabar Order Generation sets your strategy to be evaluated on every single tick as a bar is built. If Intrabar Order Generation is enabled, the strategy can generate orders as soon as the criteria or conditions are met instead of generating strategy orders only at the close of a bar; in fact, entry and/or exit orders may be generated multiple times within a bar.
Intrabar Order Generation may also be used in backtesting. In this case, a strategy will not evaluate its conditions and criteria only at the close of every historical bar, but it will also evaluate them at the open, high and low. Strategy orders will be generated and executed as conditions and criteria are met, based on all four of these price points.
Although Intrabar Order Generation makes the strategy evaluate and calculate on every single tick that occurs real-time, it does not know the detailed trade information (other than the four price points mentioned above) that occurred in a historical bar. Look-Inside-Bar Backtesting can and should be used to supply that information.