Abstract: A system and method of providing control of prices in an on screen window having a price held for further transactions on an interface for traders of financial instruments. The interface contains a display of products for trading and respective prices for bids and offers. The user has a control device such as a computer mouse with a roller control. Selection of a particular product results in the display of the price of the product at the instant time the product is selected. The price is held until a confirming key or mouse stroke is received to initiate a trading action such as placing a new order, killing an existing order or hitting or lifting an order. The price can be altered by means of the roller control.