A key to understanding the A way of reading the market that recognizes either time spent or volume traded at a particular price level. A market profile can be either made up of “TPO’s” (time price opportunities), or volume. TPO’s measure how much time was spent at a particular price, while volume-based market profiles measure how much volume traded at a particular price. Generally, market profile is used in the trading of futures, especially the /ES. ShadowTrader utilizes volume based profiles. as Peter plots it using WindoTrader.