Premarket gappers ranked live from 4:00 ET to the opening bell
Our pre market scanner lists every US stock trading away from its prior close before the open, sorted by gap %, with the numbers you need to judge it in seconds: premarket volume, float, relative volume and price. You build a short list by 9:25 ET instead of scrolling through headlines.
A gap scanner that updates through the whole premarket
Extended hours trading starts at 4:00 ET. Volume is thin until around 7:00 ET, picks up after 8:00 ET when economic data and many earnings releases hit, and builds into the 9:30 ET open. The gap scanner refreshes on licensed real-time US market data throughout, so a stock that gaps 4% at 6:00 ET and 22% at 8:45 ET moves up your list as it happens.
- Gap % against the prior regular session close.
- Premarket volume, and premarket volume as a share of the average daily volume.
- Float in millions of shares.
- Relative volume for this time of the premarket.
- Premarket high and low, the two levels most traders mark.
- Last price and spread, to avoid names you cannot fill.
Default filters for premarket gappers
The demo on our homepage starts with a price between $2 and $20, a minimum gap of 10% and relative volume above 3x. Those are reasonable starting points for small cap momentum, not rules. Larger account traders often raise the minimum price to $10 and drop the float filter, because higher priced gappers with deep liquidity let them trade more size with tighter spreads. Change any field, save the scan and it loads with your settings each morning.
Four checks before a premarket gapper reaches your watchlist
A big gap is a starting point. Before a name earns a place on your day trading watchlist, most experienced traders run through the same short list.
- Catalyst. Earnings, an FDA decision, a contract, an offering, or nothing at all. A gap without news behaves very differently from a gap on a material announcement. The scanner shows the gap, and you check the headline.
- Float. Under 20M shares can move violently in both directions. Over 100M usually needs heavy volume to keep going.
- Premarket volume. A 40% gap on 30,000 shares is a quote, not a market. Many traders want at least a few hundred thousand shares by 9:00 ET.
- Relative volume. RVOL above 5x in the premarket says the stock is getting real attention, not just a few prints.
Gap and go, gap and fade
Some gappers hold the premarket high and push through it after the open. Others fade the whole gap by 10:00 ET. The scanner cannot tell you which one you are looking at. What it can do is put the premarket high on the screen and let you set a trading alerts condition on a break above it or a cross below VWAP, so you react to what price does rather than what you hope it will do.
Watch out for offerings and halts
Small caps that gap on news sometimes announce a share offering during the premarket or right after the open, and the gap can disappear in minutes. Names that open far from the prior close can also be halted in the first minutes under limit up limit down rules. Plan your size with the position size calculator before the bell, not after the first candle.
A premarket routine you can repeat
A routine that suits many traders looks like this.
- 7:00 ET. Open the premarket gappers scan, skim anything above a 10% gap.
- 8:00 to 8:45 ET. Read the catalyst on the top names, drop anything without news or with an offering.
- 9:00 ET. Check premarket volume and float, cut the list to five or fewer.
- 9:15 ET. Mark premarket high, low and the prior day's close on each name, set alerts.
- 9:25 ET. Decide your maximum loss per trade and your daily stop, then wait for the open.
After the bell, switch to the stock scanners for day trading presets for the open and the first hour.
Which gaps actually pay for you
Every trade logged in the journal keeps the gap %, float, RVOL and entry time from the scan. After a few dozen trades the analytics can show whether your gaps between 10% and 20% have a better average R than gaps above 40%, or whether entries in the first 5 minutes cost you more than they make. That answer comes from your own trades, not from anyone's promises.
Past performance and backtests do not guarantee future results. Trading involves substantial risk of loss.
FAQ
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When does the premarket scanner start
At 4:00 ET, when US extended hours trading begins, and it runs to the 9:30 ET open, then continues into the regular session.
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How is the gap calculated
Gap % is the current premarket price compared with the prior regular session close at 16:00 ET.
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Does it show the news catalyst
The scanner shows the numbers: gap, float, volume and RVOL. You check the headline with your own news source before you trade it.
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Can I see premarket gappers without an account
Yes. The sample scan on the homepage runs on a recorded sample session and shows three rows. The live scanner needs an account and a paid plan.