# Scan the pre-market

> Scan pre-market movers from 04:00 ET in Scalpel: what the gainers, volume spike and gap scans show before the open, gap and go, and what changes at 09:30.

Source: https://scalpeltrade.com/guides/premarket-scanning
Guide 8.3, Scanner. Intermediate, 6 min read.
Checked with Scalpel 1.12.8 on 2026-10-15. By Scalpel Team.

**In short:**

Scalpel scans the pre-market from 04:00 ET. The IBKR scanner's top gainers, 3 minute volume spikes, halts and hot by volume all run before the open, with change measured against yesterday's close, while the gappers scan stays empty until 09:30. High of day momentum, Running up and four of the six setups work pre-market too; gap and go and HOD break start at the open, when gap and go fires on the first cross above the pre-market high.

Scalpel is built for the pre-market first. The small caps that run hardest often do it between 07:00 and 09:30 ET, on overnight news, with thin books and few traders watching. The scanner is ready for that: nothing waits for the opening bell except the one scan that cannot work without an open price. This guide covers what each scan does before 09:30, how to read the numbers when volume is thin, gap and go, and what changes at the open.

**Before you start:**

- The IBKR scanner set up on a scan desk ([guide 8.1](https://scalpeltrade.com/guides/set-up-ibkr-scanner)).
- TWS logged in before you want to scan. IBKR's scanner and quotes run from 04:00 ET.
- Intel turned on, so the catalyst and dilution chips are there when news breaks ([guide 9.1](https://scalpeltrade.com/guides/set-up-intel)).

## What runs before 09:30

| Scan or column | In the pre-market |
|---|---|
| **IBKR scanner** | Top gainers, 3 minute volume spikes, halts and hot by volume run from 04:00 ET. **Gappers** is empty until 09:30, because a gap is measured to the opening price |
| **CHG%** | Against yesterday's close, pre-market trading included |
| **VOL**, **Min volume** | Pre-market shares count |
| **RVOL** | Today's volume so far against the 90-day average for a whole day, so it starts low and climbs through the morning |
| **High of day momentum** | Works. The high of day includes the pre-market |
| **Running up** | Works, with its own filters |
| **Setups** | Bull flag (F), flat top (T), micro pullback (M) and consecutive run (R) work once Scalpel has a few minutes of 1-minute candles. Gap and go (G) and HOD break (H) wait for the open |
| **Intel** | SEC filings are checked every 5 seconds from 06:00 ET on weekdays, and every 2 minutes outside 06:00 to 22:00. Headlines from your IBKR news providers arrive around the clock |

*Screenshot: The header clock at 07:42 ET, reading Pre-market, over the IBKR scanner: four gappers ranked by change, with their catalyst and dilution chips. Demo data.*

**Tip.**

Read RVOL against the clock. A stock showing 2.0x at 07:30 has already traded two full average days of volume before the open, which is enormous. The same 2.0x at 15:30 is unremarkable.

## Gap and go

A gap and go is the classic open for a stock that gapped up overnight: it holds its gains in the pre-market, then breaks above the pre-market high once the regular session starts. It is one of the momentum patterns taught by Ross Cameron of Warrior Trading, whose style inspired Scalpel's scans (Scalpel is independent, not affiliated with or endorsed by him or Warrior Trading).

Scalpel tracks each listed stock's pre-market high, read from IBKR's history when the stock joins the list and kept up to date from the live trades. After 09:30, the first trade back above that high puts a green **G** chip on the row and calls out **Gap and go**. It fires once per stock per day. If the stock already crossed its pre-market high after the open before it reached the list, the gap and go has happened and Scalpel will not call a later cross one.

## A pre-market scanning routine

1. **From 07:00, read the list.** Early on, the list can be short. If it is empty, lower **Min change %** to 5 for now ([guide 8.1](https://scalpeltrade.com/guides/set-up-ibkr-scanner)).
2. **Check why each stock is moving.** The catalyst chip in the INTEL column says what the news is and how strong ([guide 9.4](https://scalpeltrade.com/guides/catalyst-grading)). No chip means no headline on file.
3. **Strike out the sellers.** A red **Selling** or amber **Dilution** chip means the company can sell stock into your move. A red **Offering** chip is an offering headline ([guide 9.2](https://scalpeltrade.com/guides/check-dilution)).
4. **Look at the supply.** SHS OUT and the squeeze score ([guide 8.4](https://scalpeltrade.com/guides/shares-out-short-interest-squeeze)) show which names can move fast on little buying.
5. **Load the best two or three onto desks** with the coloured squares, and watch their Level 2 and tape.
6. **At 09:30,** expect the list to reshuffle as the gappers scan fills in, and watch for G chips.

[Guide 14.2](https://scalpeltrade.com/guides/premarket-routine) turns this into a full morning routine.

## What changes at 09:30

- **The gappers scan fills.** It can add a burst of names in the first minute, each one ringing the bell once. The bell rings at most once every 1.5 seconds; every alert is kept in the panel's LOG view.
- **Gap and go and HOD break go live** on the Setups panel.
- **Liquidity arrives.** Spreads usually tighten and the book thickens. Pre-market prints on thin books are easy to push around, so a pre-market high can be a single print.

**Careful.**

Pre-market trading is thin and fast. Outside regular hours US exchanges take limit orders only, spreads are wide, and a stock can drop through several price levels in one print. That is why Scalpel's stops are watched by the app and sent as marketable limit orders flagged for extended hours, rather than resting stop orders that cannot work before the open ([guide 5.1](https://scalpeltrade.com/guides/how-stops-work)). Even so, an exit can fill well below your stop. Pre-market momentum trading carries a significant risk of loss: start in SIM and keep your size small.

## What can go wrong

- **The list is empty at 05:00.** Few stocks are up 10% that early on real volume. Lower **Min change %**, or clear **Min volume**, which counts only the few shares traded so far.
- **No intel chips on a pre-market runner.** The stock may be past the 40-symbol intel limit, or the news has not reached your IBKR news providers yet. Check that intel is on and watching ([guide 9.1](https://scalpeltrade.com/guides/set-up-intel)).
- **No G chip on a stock that clearly gapped and went.** It crossed its pre-market high before it joined the list, or before Scalpel was running.

## Questions

**What time does Scalpel's scanner start?**

As soon as IBKR's scanner returns results, from 04:00 ET on trading days, as long as TWS or IB Gateway is logged in and Scalpel is connected.

**Why is the gappers scan empty in the pre-market?**

IBKR's gappers scan measures the gap from yesterday's close to today's open, and there is no opening price until 09:30. The top gainers scan covers pre-market gaps until then.

**Is percent change in the pre-market against yesterday's close?**

Yes. CHG% and Min change % compare the last price, pre-market included, with the previous session's close.

**Can I trade pre-market in Scalpel?**

Yes. Pre-market, regular hours and after-hours all trade. Entries are marketable limit orders and Extended-hours fills is on by default in Settings > Trading; exits can always fill outside regular hours. Stops are watched by the app, so Scalpel must stay running.

**Does the pre-market high include the first minutes after 04:00?**

Yes. The pre-market high is the highest trade from 04:00 ET to the open, read from IBKR's 1-minute history when a stock joins the list and kept current from live trades after that.