J. Peter Steidlmayer developed Market Profile in the 1980s in conjunction with the Chicago Board of Trade. Market Profile is a graphical organization of price and time information. It displays price on the vertical axis and time on the horizontal axis. Letters are used to symbolize time brackets. This type of chart is mostly used on an intra-day basis. The trading day is divided into 30 minute periods, called TPO’s (Time Price Opportunities). Each time the market trades at a price that hasn’t occured in a prior TPO, a letter is marked at that price. The letters produce a view of prices that have traded in the most and least time frames. Market Profile reveals pricing patterns and which price areas the market is accepting or rejecting. It suggests that a price level that has been confirmed over time assumes a greater significance. Conversely, a price that is touched only briefly is less important. The concept of Market Profile is derived from the idea that markets have a form of organization determined by time, price, and volume. Each day, the market will develop a range for the day and a value area, which represents an equilibrium point where there are an equal number of buyers and sellers.