MERIDIANGAP TERMINAL
New York · ET
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Session
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Opens in
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Data freshness
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Data feedDemo

Control

500 SYMBOLS
Gap Up
0
Gap Down
0
Filled
0 / 0
Avg fill
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Universe scanned
0 / 500
Universe
Pulls official sector data for the tickers currently on your board and caches it. Curated map is used until then.
Each filter hides gaps that don't qualify. Leave at 0 to turn a filter off.
Skip cheap stocks — only show ones trading above this
Skip illiquid names — needs this many shares traded yesterday
Only unusually active stocks. 2× = twice normal volume
Only bigger gaps — hide ones smaller than this %
Only smaller-cap names (fewer shares = bigger moves). Run "Fetch real sectors" first
Auto-scan at open
Fires 09:30:00 ET · Mon–Fri
Live re-scan
Every 60s while open
Precise open
Confirm official 09:30 print
Pre-market scan
Show forming gaps 4:00–9:30 ET (provisional)
Alerts
Sound + notify on new gaps
Scan log
Idle — awaiting trigger.
Fill log clear
No gaps filled yet.
Educational tool · not financial advice. Data may be delayed depending on your plan. Always verify before trading.
MERIDIAN · v1.0 · demo

Opening Gaps

— signals
Symbol Dir Open Prior H/L Gap $ Gap % RVOL Score▼ To Fill ● Time

No scan run yet.

1
Pick a data source
Tap ⚙ — start in Demo to explore, or connect Polygon/Alpaca for live data.
2
Run a scan
Hit Run scan now, or leave Auto-scan on and it fires at 09:30 ET.
3
Watch gaps fill
Each signal tracks its live $ gap. At 100% it’s marked FILLED and logged with its fill time.

Gap Anatomy

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Open
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Prior High
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Prior Low
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Gap $
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Gap %
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RVOL
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Quality
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To Fill
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Select a signal to see its gap anatomy —
where price sits, and how far it must travel to fill.

Fill progress—
saved

Connection & Settings

Two ways to connect: Backend (recommended) — your key sits on a tiny serverless proxy, never in the browser, and CORS is solved. Direct — paste the key here for quick testing. Demo runs offline so you can see the UI working.
Backend deploy: see PROXY-SETUP.md — paste polygon-proxy.worker.js into a Cloudflare Worker, set POLYGON_API_KEY as a secret, and put the Worker URL above. Takes about 3 minutes.
Alert customization
The “approaching fill” zone many traders watch for entries.
Directional chimes
Rising tone ▲ up · falling tone ▼ down
Note
Direct keys are held in memory for this session only and never persisted. Backend mode keeps the key entirely off the client.

Gap Detection Logic

At the 09:30 ET open each weekday, every symbol in the universe is evaluated against its prior regular session:

▲ GAP UP  when  open > prior day HIGH
▼ GAP DOWN  when  open < prior day LOW

Gap magnitude is measured from the breached level:
up% = (open − priorHigh) / priorHigh
down% = (open − priorLow) / priorLow
Prior High / Low use the regular session only. Today’s open is the official 09:30 print. Holidays are not yet in the calendar — I can add an exchange-holiday table so the scanner skips closed days automatically.

Fill History & Stats

No gaps filled yet.
History is saved on this device, per trading day (last 60 days). It survives reloads and reflects gaps that fully filled while the scanner was running. Demo fills are saved too — they’ll clear naturally once you’re on live data.

Open Gaps · carried forward

Still open
No open gaps tracked yet. Run scans and unfilled gaps will collect here.
Recently filled (took > 1 day)
None yet.
Unfilled gaps are carried day to day until they fill or 30 trading days pass. A gap from a prior day is re-checked whenever that ticker appears in a scan (or ticks live). Saved on this device.