Gappers
gap%≥10price≥1rvol≥5
AVTX+22%QNRX+15%GXAI+19%MEGL+31%HOLO+12%
Find runners before they run.
Real-time stock scanner that scans the whole US market every second — computing every metric down to 10-second rolling windows. Catch the surge in its first ticks, not the third candle.
5k+
tickers scanned live, every second
10s
smallest window
4AM–8PM
all three sessions
~50
filterable metrics
01 — Parallel scanning
Run 10+ real-time stock scans in parallel.
Ten or more independent live stock scanners running side by side — gappers, RVOL leaders, low-float squeezes, momentum, halts. Each is its own filter group, evaluated against the full universe every second. You're not flipping between screens or re-running a stock screener; the whole market is laid out in front of you.
02 — Session-aware
Numbers scoped to the session, not the day.
Full pre-market, regular hours, and after-hours, with every metric computed per session. Earnings, FDA rulings, and institutional blocks land outside regular hours, and historically that's where most of a stock's price change happens. Session-scoped metrics make those moves read as loudly as they trade.
Pre-market04:00 – 09:30
Regular hours09:30 – 16:00
14:00 vol spike
After-hours16:00 – 20:00
16:45 news
Change %
Relative volume
Volume
Dollar volume
—Subsecond
—
flips to today's close at 16:00
—
vs this session's own norm
—
resets 04:00 · 09:30 · 16:00
—
this session's tape only
Full dayevery scanner (including ours)
—
vs yesterday's close, frozen at 16:00
—
—
4 AM → 8 PM, never resets
—
the day's running total
Drag the timeline: the top row re-baselines itself at 04:00, 09:30, and 16:00, while the bottom row is the same day-wide math every scanner shows. Illustrative demo data — yesterday's close $4.12, official open $4.58.
03 — Rolling windows
See the spike while it's still spiking.
Ever wondered which stock just spiked 5% in the last ten seconds? Most scanners can't answer that. They track the day's running total, and a ten-second surge is a rounding error in a day number. Subsecond runs five rolling windows at once, 10s through 15m, so the surge shows up in the first ticks. Press the button and see it happen.
A 10 second window sees the move while the day number is still averaging it away. Every scanner can watch day change, and here that rule stays silent until TSLA has already crossed $358. Subsecond fires about 5 seconds into the move, near $346, about 40 seconds and $11 earlier.
Illustrative demo data, played back at 2x speed. The spike replays on a loop.
04 — Layouts
Build your battlestation.
Drag-and-resize grid panels, pick columns per scan, set sort order, color-code views. Save unlimited layouts and switch in one click. Reuse the same scan everywhere — edit its rules once, every panel updates instantly.
Premarket Gap
Mid-Day Momentum
Research
5,000+
The whole US market
Every ticker on a 1 Hz tick. Only the changes are pushed to you, instantly. Nothing slips through.
50-day
Honest RVOL
10-second bins, computed per session, with a noise floor so fresh IPOs don't fake a 25× reading.
Nightly
Squeeze data
Filter on float, short interest, days-to-cover and short % of float — refreshed every night.
~50
Composable metrics
Price, volume, gap%, RVOL, $vol, float, short data — chained with ≥ / ≤ / range and AND logic.
Data coverage
Every venue on the consolidated tape.
Subsecond scans the full consolidated US equities tape — every print from every major exchange, not a sampled subset.
Pricing
Built for traders who move first.
Try it for 30 days, then run it monthly — or save 18% on the year.
OR JUST TRY IT
$2930-day trial
Full access for 30 days. No auto-renewal.
Everything included
- All 10+ live scans at once
- All three sessions, 4 AM – 8 PM
- Five rolling windows, down to 10s
- Full squeeze & short data
- All ~50 filterable metrics
- Unlimited layouts & priority support
Cancel anytime · upgrade, downgrade or switch billing whenever you like
Questions, answered.
How is this different from a normal scanner?
Most scanners run one filter at a time and stop at the 1-minute bar. Subsecond runs 10 or more independent scans in parallel against all 5,000+ US tickers, re-evaluated every second, with rolling windows down to 10 seconds — so you see surges before they print.
Does it really cover pre-market and after-hours?
Yes — 4 AM to 8 PM ET across all three sessions. Crucially, the metrics are computed per session: pre-market RVOL compares to pre-market history, gap % re-anchors to the 9:30 open, and after-hours baselines flip to today's close. No manual resets.
What is intra-minute scanning?
Intra-minute scanning reads a stock's move inside the current candle instead of waiting for it to close. A 1-minute scanner can only tell you what happened after the bar prints; Subsecond's 10s and 30s rolling windows surface the surge while the minute is still forming — typically 30–90 seconds earlier.
What does '10-second granularity' actually mean?
Five rolling windows run simultaneously: 10s, 30s, 1m, 5m and 15m. Your 10s and 30s windows catch a volume surge 30–90 seconds before a 1-minute-bar scanner can even register it.
Is Subsecond a stock scanner or a stock screener?
Both — it is a live stock scanner and a real-time stock screener in one. A stock screener filters the market on a static snapshot; a live stock scanner re-evaluates those filters continuously. Subsecond re-runs every one of your scans each second against the full US market, so the same rules that would give you an end-of-day screen give you a live watchlist instead.
Can I save and switch between layouts?
Unlimited custom layouts, each with multiple resizable grid views, per-view column config, sort order and color coding. Reuse the same scan across layouts — edit its rules once and every panel updates instantly.
Is the relative volume trustworthy?
RVOL uses a 50-day baseline in 10-second bins, computed per session, with a noise floor so newly-listed tickers and thin names don't produce fake 25× readings. Unusual-volume detection that's accurate sub-minute.
Do I need a credit card to try it?
The 30-day trial is a one-time $29 charge with no auto-renewal — you're never silently rolled into a subscription. Upgrade to monthly or yearly whenever you're ready.
Win the open.
The whole US market, re-scanned every second, on one screen. Stop hunting between tabs — start seeing the move first.
$29 for a 30-day trial · no auto-renewal