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Data delays & limits
Every data source has limits. Trading on a delayed quote or making an OSINT call from sparse data can be expensive — this page documents what's known about each provider.
Quote latency by source
| Provider | Tier | Typical latency |
|---|---|---|
| EODHD | Free | EOD only — no intraday |
| EODHD | Paid | Real-time on US equities; 5–15 min delayed on others; EOD ~1 session after close |
| Finnhub | Free | ~15 min delayed on some exchanges; near-real-time for US |
| Finnhub | Paid | Sub-second for supported exchanges |
| Yahoo | Free | Near-real-time WTI; ~15 min on most indices |
The Market panel shows a realtime / delayed badge — trust the badge, not the gut feel.
Per-exchange behaviour in the Market dashboard
| Exchange | Realtime? | Notes |
|---|---|---|
| NYSE / NASDAQ | Real-time (EODHD bulk) | The default; refresh every 30s |
| LSE / FRA / HKEX / TSE / ASX | EOD fallback | Most recent daily bar — see MARKET_SNAPSHOT_EOD_FALLBACK_LIMIT (default 120 symbols per request) |
| Off-hours / weekends / holidays | EOD fallback for all | Snapshot TTL extends to 10 min |
Polling intervals
| Surface | Interval |
|---|---|
| Market panel quotes | 30s (REST, paused when hidden) |
| Market dashboard snapshot | 60s in market hours, 10 min off-hours |
| News rail (dashboard side panel) | 5 min |
| Fear & Greed gauge | 1h |
| Aircraft positions | 30s (OpenSky) |
| Vessel positions | 60s |
Coverage gaps
AIS (vessels)
- Coastal waters: dense, frequent updates.
- Mid-ocean: position updates can lag tens of minutes to hours, depending on satellite reception.
- Vessels can voluntarily disable AIS — absence of pin ≠ absence of vessel.
- Pleasure craft and small fishing vessels typically don't broadcast AIS.
ADS-B (aircraft)
- Europe, North America, parts of Asia: dense.
- Oceans, polar regions, remote interiors: sparse to nonexistent.
- Some military, government, and certain GA aircraft transmit limited or no ADS-B.
- OpenSky free-tier polling interval: ~10 seconds. Paid tier: faster.
News
- Source coverage varies by language and region.
- Geolocation precision is tag-level — a story tagged "Hormuz" pins to a region centroid, not the actual vessel/event.
Equities
- Finnhub indexes most major exchanges but not every emerging-market venue.
- EODHD fundamentals lag the actual filing — we surface what the provider has parsed.
Rate limits
Atlas applies upstream rate limits via asyncio.Semaphore (see backend/services/market_data.py). Concurrent requests are throttled to stay below provider limits. If you see backend logs about 429s, the limit was breached upstream — the proxy doesn't paper over it.
AI Chat token caps
The AI chat has a cap on the prompt context window (varies by configured model — see Changelog for the active model). Practical implications:
- A news screen with hundreds of headlines is summarized in chunks; very large screens may produce a "summary of summary" rather than a single ground-truth pass.
- Long transcripts may be truncated at the boundary — focus the section you care about before asking.
What this means in practice
- For trading decisions, check the Market panel's realtime/delayed badge before each trade. The free Finnhub tier is fine for educational use, not for execution.
- For OSINT investigations, treat absent pins as ambiguous — verify with a second source (a major maritime tracker, an alternative ADS-B feed) before drawing conclusions.
- For fundamental analysis, EODHD typically lags actual filings by hours to days — for breaking 8-K commentary, read the filing directly rather than waiting for it to appear in Disclosures.