Teams do not buy a market breadth API use cases for the sake of an endpoint. They buy it to screen, alert, backtest, or answer a question an agent should not hallucinate. Here is how this one actually gets used.
How quants, fintechs, and AI apps use Eulerpool market breadth — screens, alerts, agents, and research notebooks.
What the data contains
- Advance/decline, new highs/lows, McClellan, TRIN, percent above 50/200 DMA
- Exchange-level so NYSE breadth is not mixed with Nasdaq
- The internals tape used to sanity-check index breakouts
The endpoint
Primary path /v1/breadth/advance-decline. Authenticate with a Bearer token. Errors are JSON with a stable code field so retries are mechanical.
curl -H 'Authorization: Bearer YOUR_KEY' \
'https://api.eulerpool.com/v1/breadth/advance-decline'Authentication
Send Authorization: Bearer YOUR_KEY. Keys are created at register in under a minute. Official SDKs take the key in the constructor; Excel stores it in the add-in settings. There is no key-in-query-string mode — do not paste tokens into public notebooks.
Primary route for this article: /v1/breadth/advance-decline. Docs: /financial-data-api.
Coverage and freshness
Eulerpool maps 100,000+ securities across 90+ exchanges. market breadth API use cases rides that same reference layer — identifiers resolve through ticker, name, ISIN, or CUSIP via search, so a European name is not a dead end. History depth depends on the source: prices go back decades, 1-minute bars to 2010, 13F to 2013, macro often 50+ years.
Paid plans can stream quotes over WebSocket; the free plan uses REST with a 15-minute delay on real-time equity fields. Fundamentals, ownership, and calendars are identical on every plan. Rate-limit headers ship on every response. Batch routes (up to 100 symbols) count as one request.
Typical builds
Internal research portals, customer-facing quote boards, earnings-alert bots, factor notebooks, and agent tools that need a number they can cite. If your use case needs redistribution, read licensing before you ship.
Fit versus other sources
Most teams land here after fighting Yahoo Finance scrapers, Alpha Vantage’s 25-request/day ceiling, or a Polygon bill that ignored fundamentals. Eulerpool is a licensed market breadth API use cases with statements, estimates, filings, and macro on the same key — and a terms of service you can actually show legal.
Deep comparisons live here: vs Alpha Vantage, vs Polygon, Yahoo Finance alternative, best stock market APIs in 2026.
Who should call this
- Quant research — pandas/R dataframes, point-in-time fields, 20+ years of history where the source publishes it.
- Fintech apps — watchlists, screeners, and portfolio views without relicensing Bloomberg for every customer.
- AI agents — typed JSON and a native MCP server so models stop inventing numbers for Build with the Market Breadth.
- Spreadsheets — the Excel and Google Sheets add-in covers the same endpoints as REST.
Build with the Market Breadth API is one slice of the Eulerpool Financial Data API. Adjacent routes — quotes, statements, ownership, macro — use the same key, so a prototype that starts here does not hit a wall at the second dataset.
Get started
Create a free key at eulerpool.com/developers/register — no credit card, 10,000 requests/month. Then read the market breadth API use cases docs and ship.
Every day’s drop is listed on the Financial Data API changelog. Same data powers the Eulerpool terminal 500,000+ investors already use — the API is that database with a key in front of it.