You can set up Spark to gradually improve your order price (i.e. increase price for Buy Order ; decrease price for Sell Order) Up until a Specific Time(e.g. 17:25). It is useful if you are not urgent and want to fill the order at a better price e.g. 40 points below market price for BUY order. This feature ensures the order is filled no later than 17:25. Spark will calculate the distance between you order price and the market price, and automatically improve your order price by m points gradually. You can set m = 1 or a larger value. This way, if the market moves toward your order price, you get a good price filled. If the market moves away from your order price, you still get it filled eventually after N minutes.
You can see in the above log (and below) that the order price got improved incrementally, many times by 1 point.
This function can also be used in Options Implied Volatitilty: