A Participate order, only available through GSAT, attempts to achieve the percentage of the primary market volume you specify by watching and reacting to real-time stock volume.
The Participate algorithm processes orders differently for European symbols; by default, participation calculations are based on the historical volume profile. However, you can submit aggressive Participate orders that watch and react to real-time stock volume in order to maintain the desired participation level; if you select Aggressive from the Style drop-down list box and the participation rate falls more than 10% below the primary market volume, GSAT will submit orders to catch up.