Aggressors are traders who exchange products at market prices. Aggressors either buy or sell at current bid sale price compared to entering limit orders.
Instigators execute their orders immediately as they purchase available contracts found at the current market price. Instigators sell at lower and cheaper prices and buying at higher and higher prices, pushing other stock traders out of the market. Passive traders, as opposed, add fluidity to the forex market by positioning bids and will be offering.