How our data works

A market terminal is only as good as its honesty about where numbers come from, how fresh they are, and where they can be wrong. This page states exactly that. The one rule behind everything here: never publish a number without a source and an as-of timestamp.

Sources

• Equity prices, index levels, volume, deals, market cap: aggregated from official exchange publications and established market-data sources, with multi-source redundancy — if a primary source is unavailable, a secondary source and our own stored snapshot take over automatically, and every payload records which source produced it.
• Corporate disclosures: official corporate disclosure publications, fetched twice daily (6:00 AM and 6:00 PM WAT).
• NASD OTC securities: NASD OTC Securities Exchange published data, refreshed during OTC trading windows. NASD prices reflect the last negotiated trade and update daily.
• Dividends: aggregated from official corporate actions and public filings, best-effort.
• FX rates: third-party exchange-rate providers with two-source redundancy, refreshed roughly every 30 minutes. Indicative rates, not tradeable quotes.

Refresh cadence

• The NGX trading session is 9:00 AM – 4:00 PM WAT, Monday to Friday.
• During the session, prices and the market board refresh approximately every 20 minutes. We say "live during market hours · updated every 20 minutes" everywhere, and we mean exactly that — we do not claim tick-level real-time data.
• NGX often finalises settlement figures (deals, volume, the closing ASI) up to an hour or more after the 4:00 PM bell. We re-capture the close at 4:10 PM, 5:30 PM, and 8:00 PM WAT so the day's final numbers self-correct in place once the exchange publishes them.
• Outside market hours, all figures show the last completed session.

Canonical calculations

• ASI daily change % is computed from the live All-Share Index level against the previous session's official close in our stored history — never from averaging individual stock moves. One number is used across the homepage, ticker pages, the daily wrap, and the API.
• Market capitalisation comes from the exchange's published figure where available, otherwise derived from price × shares outstanding.
• As-of stamps: API responses carry as_of (when the data was fetched) and stale_after (when to stop trusting it) timestamps, and rendered pages display the as-of time they received.

Consistency guarantees

The same verified dataset powers NGX Pulse and our pan-African sister platform Mansa Markets — so whichever platform you're on, the Nigerian market numbers are identical. Automated consistency checks run every 30 minutes throughout the trading session, and any discrepancy is flagged and corrected immediately.

Known limitations

• Intraday figures between refreshes can trail the exchange by up to ~20 minutes.
• The exchange's own post-close settlement lag means closing figures published here before roughly 5:30 PM WAT may still be preliminary; they are corrected automatically the same evening.
• NGX public holidays are handled by carrying the previous close forward; holiday calendars can occasionally lag official announcements.
• Dividend histories and shares-outstanding records are maintained best-effort from public filings and may have gaps for thinly covered names.
• FX rates are indicative interbank-style rates from third-party providers, not CBN official or parallel-market quotes.

NGX Pulse is a market data and research aggregation platform, not a licensed investment adviser. Nothing on this site is investment advice.