TPO

What it is

TPO stands for Time Price Opportunity — the foundational unit of market profile, the framework developed by J. Peter Steidlmayer at the Chicago Board of Trade in the 1980s. The idea is to chop the trading session into fixed time brackets (traditionally 30 minutes), assign each bracket a letter (A, B, C, …), and at every price level the market touches during a bracket, plot that bracket's letter at that price.

The result is a horizontal letter-distribution chart: each price level shows the alphabetical sequence of the brackets during which price was there. Read top-down, the chart looks like a bell curve made of letters. The fatter parts (more letters per price) are where price spent more time; the thinner edges are where price moved through quickly.

Each letter at a price level is one TPO. The total count of TPOs at a price is the time-equivalent of that level's volume in a volume profile — but it's measuring time, not volume. A price with 8 TPOs was touched in 8 different 30-minute brackets.

Why it matters

Market profile and TPO charts are an older but still widely-followed framework, especially among CME pit-era and post-pit-era futures traders. The vocabulary built around TPO charts is rich:

• Initial Balance (IB) — the price range of the first two brackets (typically the first hour). IB sets the early structural reference for the rest of the session.
• POC, VAH, VAL — the same concepts as volume profile (most-letters price, top of 70%-TPO area, bottom of 70%-TPO area). They arose from market profile and were later applied to volume profiles.
• Single prints (in TPO terminology) — prices with only one letter, indicating fast-travel zones where the market did not pause. (Note: this is a TPO single print, distinct from the order-flow single-print concept of one-sided volume.)
• Profile shape vocabulary — D-shape (balanced), P-shape (auction higher), b-shape (auction lower), B-shape (double distribution), neutral, trend day. Each shape carries inference about the day's character.

For traders who think in market-profile terms, TPO is the lingua franca for describing what a session did and what is likely to happen tomorrow.

How it appears on Sierra Chart

Sierra Chart provides a native TPO chart type and TPO profile studies. The platform supports the standard 30-minute bracket scheme as well as custom bracket durations, and it renders the letters either as actual characters or as filled blocks color-coded by bracket. The same TPO data is used to compute the value area and the IB range.

TPO charts can be drawn on their own or overlaid on a price chart, and Sierra Chart supports merging multiple sessions into composite TPO profiles for multi-day or weekly views.

Common patterns / pitfalls

• TPO is time-based, volume profile is volume-based — the two profiles can look similar but tell different stories. A market with constant low volume across many brackets has a fat TPO profile but a thin volume profile.
• Bracket size affects shape — 30-minute is the standard convention; smaller brackets produce more resolution but more noise.
• Letter naming — letters cycle through the alphabet starting at A. Some platforms restart at A every day; others continue from where they left off. Be aware of the convention.
• Don't conflate TPO single prints with order-flow single prints — the names are similar but the concepts differ: a TPO single print is a price with one letter (visited in one bracket), an order-flow single print is a price with one-sided bid or ask volume.
• Inheritance from CME pit era — TPO terminology reflects an older market microstructure. The patterns still hold but the underlying liquidity mechanics have changed.

Related SCS studies

SCS does not ship a dedicated TPO study — Sierra Chart's built-in market profile coverage is comprehensive. SCS focuses instead on the order-flow side of the same auction-theory frame, with studies like CVD Filled Area, Delta Candle Color, and Single Print and Gap that surface tick-level imbalance signals complementary to TPO structural reading.