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Insights Erianux Session structure 14 September 2026 4 min

Reading a market profile

Brackets, TPOs, the point of control, the seventy percent value area, single prints and the day shapes, explained from the ground up.

Market Profile is a way of organising a trading day by the time spent at each price. It was developed by J. Peter Steidlmayer and introduced to traders by the Chicago Board of Trade in the 1980s. The chart looks unusual at first, but it answers one plain question: where did the market spend its time today, and where did it only pass through?

Brackets and marks

The day is cut into periods, traditionally thirty minutes each. Every price the market traded at during a period gets a mark for that period, called a TPO, short for time price opportunity. Stack the marks sideways at each price and the day builds into a shape. Wide rows are prices the market visited again and again. Narrow rows are prices it touched once and left.

The parts that carry meaning

  • The point of control is the price with the most TPOs, where the market spent the most time.
  • The value area is the range around the point of control that holds about seventy percent of the day's TPOs. Seventy percent is a convention, chosen because it is close to one standard deviation of a normal distribution.
  • The initial balance is the range of the first hour of regular trading, traditionally the first two periods.
  • Single prints are prices traded in only one period. They mark fast moves that found no two-sided trade.
  • Tails are runs of single prints at the very top or bottom of the day, where the market probed and was turned away.

Shapes

A day that builds evenly, wide in the middle and thin at both ends, is balanced. Buyers and sellers agreed on a range. A day that is wide at the top with a long thin tail below is often called a P shape. The market rose quickly and then built value higher, which is common when short sellers are covering. The mirror image, wide at the bottom, is a b shape, often seen when holders of long positions are selling out. A day with two separate wide areas joined by thin trade is a double distribution. Something changed during the session, and the market moved to a new area of value.

Excess and poor extremes. A tail at the day's high or low shows the market reached a price that was firmly rejected, which is called excess. A high or low with no tail, where several periods traded flat at the extreme, is called poor. The auction there looks unfinished, and poor highs and lows are often revisited.

What to actually do with it

  • Read yesterday's shape before today's open. It tells you whether the market was balanced or moving.
  • Note single prints and poor extremes, because they are the prices most likely to matter again.
  • Compare today's value area with yesterday's. Higher, lower or overlapping describes direction better than any single candle.
  • Remember that a profile describes where time was spent. It does not predict. It gives you the context for judging what price does next.