A Pegged-to-Primary Order allows you to enter a more aggressive price than the current market price, and have the entered price stay within a fixed interval to the market, should prices deteriorate. A Buy order is pegged to the bid (instead of the best offer) and a Sell order is pegged to the offer. You can enter an offset amount that is added to a buy order price and subtracted from a sell price.

For a buy order, the order is submitted at the best bid, with the offset amount (if used) added to the best bid. If the best bid moves before the order executes, your order price is modified to match to the new best bid with the offset amount added.

For a sell order, the order is submitted at the best offer, with the offset amount (if used) subtracted from the best offer. If the best offer moves before the order executes, your order price is modified to match to the new best offer, with the offset amount subtracted.