Who this entry is for — Anyone who treats every spike as a valid breakout. In the CBOT Market Profile, range extension is range lengthening when the longer-term participant breaks existing balance with real volume.
Source: CBOT, Market Profile Home Study Guide, Part I — Range Extension. Raw:
raw/sources/steidlmayer/ingest-cbot-market-profile.
Prerequisites
Initial Balance, Initiating vs responsive.
What range extension is
During a session the market forms a price range (often initially within the Initial Balance). When a longer-term trader enters with enough volume to tilt the auction, the range extends beyond the prior balance area: that is range extension.
| Direction | Who «pushes» | Auction logic |
|---|---|---|
| Extension up | Aggressive longer-term buying | Market rises to shut off buying |
| Extension down | Aggressive longer-term selling | Market falls to shut off selling |
Not every new high/low is extension: you need initiating activity with longer-term participation, not short-term noise alone.
Extension + opposite extreme
If you see range extension up followed by responsive selling at the high extreme, the typical sequence is:
- Extension up (initiating buy breaks balance)
- Competitive selling forms the extreme — market tests whether the new price is accepted
Reading event order avoids entering the first spike without context.
Teaching example — Tight IB, then extension down below yesterday's VA with initiating sell. A b-type (trend) day is more likely than a P (rotation) day. See day types.
Extension vs fake move
| Signal | «Real» extension | Fragile move |
|---|---|---|
| Activity | Longer-term initiating | Responsive / thin volume only |
| Value | New area forming | Quick return to prior VA |
| Extremes | Test with opposite activity | Isolated spike, no follow-through |