Field notes for the Eulerpool stock seasonality json api. Stable names, ISO timestamps, numeric types — the contract you want if a second service is going to depend on this response.
Field-level tour of the Eulerpool seasonality patterns endpoint — what you get, how it’s updated, and how it counts against quota.
What the data contains
- Average monthly and day-of-week returns with t-stats and p-values
- Pre-earnings, ex-dividend, and OpEx week effects
- 20+ years of history — not a three-year toy sample
Example request
Swap SPY for any listed identifier (ticker, and for many routes ISIN via search). Batch routes exist when you outgrow one-symbol GETs.
curl -H 'Authorization: Bearer YOUR_KEY' \
'https://api.eulerpool.com/v1/seasonality/{ticker}/monthly'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/seasonality/{ticker}/monthly. Docs: /financial-data-api.
Coverage and freshness
Eulerpool maps 100,000+ securities across 90+ exchanges. stock seasonality json api 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.
Quota and batching
One GET is one request. Batch endpoints (where available) pack up to 100 symbols and still count as one. Bulk Parquet/CSV exports exist when REST is the wrong shape. Headers on every response tell you what you have left.
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 stock seasonality json api 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 Stock Seasonality JSON.
- Spreadsheets — the Excel and Google Sheets add-in covers the same endpoints as REST.
Stock Seasonality JSON 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 stock seasonality json api 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.