A method of displaying a performance indicator symbol upon a price chart, the method includes receiving, from a first data source, user account transaction data of a trade of a quantity of units of a market-traded object transacted at a first time at an average cost per unit, the trade indicative of opening a trading position in the market-traded object, receiving, from a second data source different from the first data source, market data including a last price of the market-traded object that occurred at a second time, wherein the second time occurred after the first time, determining an average price from the last price and the average cost per unit, and generating and displaying, by a charting engine, the performance indicator symbol at a particular position, by drawing upon the price chart of the market-traded object, a first line from the average cost per unit at the first time to the average price at the second time and drawing a second line from the average price at the second time to the last price at the second time.