RTH open liquidity map — when size is allowed

[Fairman]

RTH open liquidity map: when size is allowed on liquid US names.

Rough desk map (adapt to your playbook, don't worship the clock alone):

09:30–09:35 — observe or cut size only, unless a predefined open-drive is already on the sheet
09:35–10:00 — A-setups at normal size if spread is acceptable
10:00–11:30 — continuation or stand down
11:30–14:00 — chop risk up; reduce
14:00–16:00 — re-engage only if the playbook says so

Liquidity is not permission. Permission is written playbook + acceptable spread + daily risk still open.

A worked example of how the map changes one trade across the day. Same name, same setup: a pullback hold with 10 cents of risk, normal size 500 shares.

At 09:33 ET the spread is 3 cents and the book is jumping. Not a predefined open-drive, so the map says observe. If I really wanted it, it would be cut size, say 200 shares, and I'd have to accept that 3 cents of spread is almost a third of my stop.

At 09:44 the spread is 1 cent and the setup triggers. That's the 09:35–10:00 window, A-setup, acceptable spread, daily risk open. Full 500 shares, about $50 of risk.

At 12:20 the same setup appears again. The spread is 1 cent, but the tape is slow and moves are overlapping. The map says reduce. 250 shares, or skip if my playbook has no midday version of this setup. Most days I skip.

At 14:30 it shows up a third time. My playbook for this name has nothing for the afternoon, so I don't re-engage.

Failure modes:

- Treating 09:35 as a starting gun instead of a permission check.
- Inventing midday trades because the morning was slow.
- Using the map on a thin name without shifting it. Thin names often never reach "acceptable spread" in the first five minutes.
- Ignoring scheduled releases, like a 10:00 ET data print, that reset the map for a few minutes.

When to skip the whole map: half days, major macro days, or any session where I've already hit my 2-loss walk-away.

Thin names: shift the whole map one notch more conservative. If your edge is open-only, say so and don't invent midday "opportunities" to stay entertained.

Diagram: session zones on one page.