# About PatternsRadar

Canonical: https://patternsradar.com/about

PatternsRadar is a stock screener for the National Stock Exchange of India, built and operated by Bitmask (https://bitmask.in), a small Indian software company. It is built around one question most screeners cannot answer: does this scan actually work? Every scan can be replayed across the last 250 sessions to measure its hit rate.

## Where the data comes from

Price, volume and delivery data come from the open-source eod2 dataset (https://github.com/BennyThadikaran/eod2) — NSE daily bars already adjusted for splits and bonuses. The database covers 3,500+ instruments and about 8.2 million daily bars, back to 1995 for the oldest listings, rebuilt every trading evening after the close. A build that fails verification leaves the previous day's data serving.

Those figures originate in the end-of-day files published by the National Stock Exchange of India. PatternsRadar is not affiliated with, endorsed by or licensed by NSE, and exchange and index names are used only to describe what the data covers.

## How the numbers are checked

All 42 indicator columns are verified against pandas-ta-classic to within one millionth, on every build. The query language's 70 reference scans are compiled and run in CI, and each sugar operator is proven to return exactly the same stocks as its longhand form.

## What it deliberately does not do

No intraday data, no live feed — the dataset updates once per session, after the close. No BSE coverage. Fundamentals (P/E, market cap, growth, shareholding) and sector are screenable but partially backfilled — missing data is NULL and never matches; sector is today's snapshot with no history. F&O fields are per-stock aggregates for the ~200 derivative stocks, not option chains. Universe tiers rank by traded turnover. The hit-rate replay is a sketch, not a full backtest: close-to-close returns, no costs, no slippage. PatternsRadar is a research tool; nothing on it is investment advice.

## Contact

Questions, corrections and bug reports are welcome — reach us through https://bitmask.in. If a number here looks wrong, we want to know more than you want to tell us.