Data methodology

Data sources

We use licensed commercial APIs and public registries. Every number shown on Ecrumena originates from one of the providers listed below — we do not produce our own price forecasts or investment recommendations.

EODHD (End of Day Historical Data)

Historical quotes for stocks, ETFs, and bonds listed on world exchanges (including the Warsaw Stock Exchange). Company fundamentals (P/E, EPS, market cap, dividend yield, sectors, industries, reported figures). Frequency: end-of-day.

AlphaVantage

Supplementary historical data and technical indicators for selected instruments. Used as a fallback when EODHD does not cover a given market.

Polygon.io

Intraday data and information about US-listed companies (NYSE, NASDAQ).

MarketStack

Additional coverage of European and Asian exchanges.

NBP (National Bank of Poland)

Currency exchange tables (used to convert foreign-currency values into PLN).

Refresh cadence

Data on public ticker pages is refreshed in automated cycles — to minimise load on external APIs and keep operating costs predictable. Every page shows the date of its most recent update.

• End-of-day quotes: daily after market close, around 22:00 CET.
• Company fundamentals (P/E, market cap, sector, dividends): daily, 02:00 CET.
• News mentions and headlines: daily, within 24 hours of publication.
• NBP currency tables: once a day, after Table A is published.
• Real-time intraday data and live tickers: not available on public pages (reserved for authenticated users in upcoming features).

Data quality validation

External APIs may contain gaps, delays, or formatting errors. We apply several mechanisms to limit their impact on what you see on the page.

• Empty or zero fields (for example a missing P/E ratio for an unprofitable company) are flagged as "no data" — we do not substitute estimated values.
• Out-of-range fields (for example negative market caps or dividends above 100%) are caught and not published until manual review.
• Company descriptions generated automatically by language models are validated against KNF-compliant vocabulary — descriptions containing recommendation-style wording are rejected.
• When the primary source returns no data, we fall back to a secondary provider (typically MarketStack or AlphaVantage). The "Data updated" stamp always reflects the most recent known date.

Selected formulas and calculations

Most numbers shown on the page come directly from a data provider. A few we compute ourselves from aggregated data — short explanations below:

Sector median

The median value of P/E, EPS, dividend yield and other sector-level indicators is computed across every company in our database that belongs to a given sector. Sector exposure depends on data-source coverage — if a sector contains fewer than 10 companies, the median is flagged as low-confidence.

Dividend yield

The sum of dividends paid in the trailing twelve months divided by the most recent close price. The figure comes directly from the data provider.

52-week range (52w high/low)

The highest and lowest closing price across the most recent 252 trading sessions. Values come directly from the data provider.

Moving averages (MA50, MA200)

Arithmetic mean of the last 50 or 200 trading-session closes. Computed by the data provider; we re-validate periodically.

News sentiment

An informational indicator — language-model classification (positive / neutral / negative) for articles mentioning the ticker, aggregated as a weighted average across the last 30 days. Sentiment is neither an investment signal, a forecast, nor a recommendation.

What we deliberately do NOT do

Ecrumena is an informational service. The following is a deliberate list of things we do not do — so it is clear what to expect from us:

• We do not publish investment recommendations (buy / sell / hold). No such guidance appears in company descriptions, sentiment, or AI summaries.
• We do not forecast future prices or earnings. All data on the page refers to historical or current state.
• We do not provide investment advisory or transaction-brokerage services. We hold no KNF licence or authorisation to provide such services.
• We do not guarantee data completeness or freshness. Tickers from smaller markets may have limited coverage or delayed updates.
• We do not expose real-time data on public pages. All numbers are end-of-previous-day unless the page explicitly states otherwise.

KNF status and informational character

Report a data issue

If you spot an issue with the data shown on a ticker page — a misspelt name, incorrect values, an outdated stamp — let us know at kontakt@ecrumena.com.