Market profile (TPO)

Market profile is a close cousin of volume profile, but it organizes the session by time at price rather than volume at price. It was developed at the Chicago Board of Trade and uses TPO — Time Price Opportunity — letters.

How a TPO profile is built

The session is divided into time periods (classically 30 minutes), each assigned a letter (A, B, C...). For every period, a letter is printed at each price the market touched during it. Stacking these horizontally builds a distribution: prices touched in many periods grow long rows of letters; prices touched briefly stay short.

Price
1.2520  A
1.2515  A B
1.2510  A B C D        <- many periods: value
1.2505  A B C D E F
1.2500    B C D E      <- many periods: value
1.2495        D E
1.2490          E

What it describes

• Value area and POC — same idea as volume profile, but derived from time spent at price rather than volume.
• Shape of the day. A tall, thin profile = a trending day (price spent little time at most levels); a wide, balanced bell = a rotational, range-bound day. Recognizing the day type early shapes whether you fade extremes or follow trend.
• Initial balance, range extension, single prints — vocabulary for how the session developed relative to its opening range.

Volume profile vs market profile

They answer different questions: volume profile asks where did the most business get done (size), market profile asks where did the market spend the most time (acceptance). Many traders use them together. Market profile, being time-based, does not need volume data, so it travels to markets (including parts of FX) where reliable volume is missing.