Tools & Data · Intermediate · 4 min
Data sources: prices, fundamentals, calendars
You can name reliable primary sources for prices, company data and economic data, tell real-time from delayed data, and check a number before relying on it.
Numbers first
Every analysis in this course rests on numbers: prices, profits, inflation rates, job figures. If a number is wrong, out of date or defined differently from what you think, the analysis built on it is wrong too, however careful it is.
The internet is full of figures, copied from site to site, often without a date or a source. A few habits help you find the original and judge whether a number can be trusted.
Go to the source
A primary source publishes a number first and is responsible for it. Everyone else repeats it.
- Prices. Exchanges publish official prices for shares and futures. For forex and CFDs, the prices you can trade at are your broker's. Data vendors and charting platforms redistribute both.
- Company data. Official filings: in the US, the SEC's free EDGAR database holds every 10-K, 10-Q and 8-K. In Europe, annual reports are published by the companies and through national storage systems. Investor relations pages link both.
- Economic data. Statistics agencies and central banks: in the US, the BLS for jobs and prices and the BEA for GDP; in Europe, Eurostat and the ECB's data portal; worldwide, the World Bank and the IMF.
- Calendars. Release dates come from the agencies themselves. Economic calendars collect them.
A note on prices: much exchange data is sold. TradingView, for example, states that most stock and futures exchanges charge fees for real-time data. Free quotes are therefore often delayed data, shown some minutes after the trade.
Who, when, how, again
Before relying on a number, run four checks:
- Who published it? A statistics agency, a filing, a vendor or an anonymous post?
- When, and how delayed? Prices can be delayed. Economic data is revised. Company figures refer to a reporting date.
- How is it defined? Trailing or forward earnings? Nominal or real growth? Adjusted or reported profit?
- Does a second source agree? If two sources differ, find out why before using either.
Example: two websites show P/E ratios of 18 and 22 for the same company. Usually neither is wrong. One uses last year's earnings, the other next year's estimates.
Common mistakes
- Trusting numbers without a date. Old figures circulate for years.
- Trading on delayed quotes. Check whether your price is real-time.
- Mixing definitions. Compare like with like: same metric, same period, same adjustment.
- Relying on copies. Go back to the publisher whenever a decision depends on the number.
The takeaway
Go to the source: exchanges and brokers for prices, filings for company data, statistics agencies for economic data. Check the date, the delay and the definition.
Check yourself
Quick quiz
4 questions. Instant feedback, nothing is saved.
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1Tap where you would find a US company's official annual report.
Tap the chart.
US public companies file their 10-K with the SEC. EDGAR makes it free to read, and companies usually link it on their investor relations page.
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2A free website shows a share price. What should you check first?
Many exchanges charge for real-time data, so free quotes are often delayed.
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3Two websites show different P/E ratios for the same company. What is the most likely reason?
Derived figures depend on definitions and inputs. Check both before comparing.
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4Where would you check an official US jobs figure?
Primary sources publish the number first, with definitions and revisions.
of 4 correct.