Charting

TPO and volume profile

The same session can be turned into a profile two ways: by time and by volume. CutlassEdge draws both, and lets you choose which one drives the value area and the POC. This page explains the difference, and the one thing worth knowing about how volume is measured.

Two measures of the same auction

  • The TPO profile measures time. Each letter (a TPO) marks 30 minutes the market traded at that price. Stacked up, the letters show where the market spent the most time. The most-lettered price is the Time POC (TPOC).
  • The volume profile measures business. Instead of counting time, it counts how many contracts traded at each price. The heaviest-volume price is the Volume POC (VPOC).

They usually point to nearly the same place, because the market tends to spend the most time where it does the most business. When they do not line up, the gap is worth noticing: the TPOC sits where the most time was spent, the VPOC where the most size traded, so a divergence flags a price that saw heavy volume in a short window, or a lot of time on thin volume.

Switching between them

It is all in the settings rail:

  • Value area, Calculate from: TPO or Volume. This chooses whether the value area and the POC are figured by time or by volume. Coverage defaults to 70 percent.
  • POC section: turn on Time POC (TPOC) and Volume POC (VPOC) to show either or both as lines on the chart. Showing both at once is the fastest way to spot a divergence.
  • Display, Profile: Letters, Blocks, or Off. Show the TPO letters, solid blocks, or hide them to read the volume bars on their own.

HVN and LVN: the shape of the volume

The volume profile also shows nodes:

  • A High Volume Node (HVN) is a heavy-volume price area, accepted value where the market is comfortable, so price tends to slow and rotate there.
  • A Low Volume Node (LVN) is a thin, quickly-rejected area the market moves through fast, and often reacts to when it comes back (these are the LVNs you also see on the Magnet map).

The one thing to know: estimated versus exact volume

This matters, so CutlassEdge is upfront about it. Where your volume numbers come from depends on your feed:

  • On an Interactive Brokers (bar) feed, the per-price volume is an estimate. Each minute's total volume is spread across the prices that minute touched. The app says so in its own words, right on the IB section: *"On bar data, per-price volume is an estimate: each minute's volume total is spread across the prices that minute touched. Prices, ranges, and TPO letters are exact."* So your prices, ranges, TPO letters, and value area are all exact; only the per-price volume split is approximated.
  • On a Databento (tick) feed, the volume-at-price is exact, counted from the executed trades. This is what powers the tick-based volume and footprint tools.

For most reads the bar estimate is perfectly usable. Where it makes a difference is the single-level detail: a real volume spike at one exact price can be smoothed away by the estimate. If that precision is what you are after, that is what the Databento feed is for (see Connect a data feed).

The TPOC trail

With the Time POC turned on, CutlassEdge also traces the POC's path through the day, one mark per period, so you can watch where the day's fair-value price migrated as the session built.