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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Scan time
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Universe scanned
0 / 500
Setup
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
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
Pulls official sector + share-count data for the tickers on your board and caches it. Needed for the share-count filter.
Idle — awaiting trigger.
Fill log clear
No gaps filled yet.
History & export
Educational tool · not financial advice. Data may be delayed depending on your plan. Always verify before trading.
MERIDIAN · v1.0 · demo

Opening Gaps

— signals
Sort
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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Select a signal to see its gap anatomy —
where price sits, and how far it must travel to fill.

Fill progress—
saved

Connection & Settings

Connection
Keys stay server-side. Live data flows through your Cloudflare Worker — API keys are never in the browser. See PROXY-SETUP.md: paste polygon-proxy.worker.js into a Worker, set its URL above, and add POLYGON_API_KEY and/or ALPACA_KEY_ID + ALPACA_SECRET_KEY as secrets (~3 min). Demo runs offline with synthetic data.
Scanning
How often the board refreshes while the market is open. Minimum 15s.
Alerts
The “approaching fill” zone many traders watch for entries.
Directional chimes
Rising tone ▲ up · falling tone ▼ down

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 (pre/post-market excluded). The scanner skips weekends and U.S. market holidays automatically via a built-in NYSE calendar.

Today's open is the official 09:30 print when your data plan delivers it. On a delayed plan (or in the first minutes after the bell), the official open may not be in yet — the scanner then uses the latest live price as a provisional open and flags it, switching to the real print once it arrives. Real-time feeds (e.g. Alpaca IEX) show opens immediately but are sourced from a single exchange, so levels can differ slightly from the full consolidated tape.

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.

Alert Center

Alerts fire when a tracked gap crosses your fill threshold or fully fills. Configure thresholds in Settings (⚙). Turn alerts on there to start receiving them.
No alerts yet this session.

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.