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How do I check a number before I make an investment decision? I trace it to its source, confirm what it measures, reproduce the calculation, test the comparison and assumptions, then investigate anything that does not reconcile. Here is the seven-check routine I use before relying on a figure in an investment decision. It draws on investment diligence and audit guidance; it is my practical synthesis, not a checklist issued by CFA Institute, the SEC, SEBI or the PCAOB, and it is not legal or personalized investment advice.
1. Where did the number come from?
Follow the figure back to its originating document or data provider. A polished chart or summary is not the same thing as evidence: identify who collected the information, how it was collected, and whether the source has an interest in the claim. When possible, distinguish a primary filing or record from a secondary account.
CFA Institute guidance tells its members and candidates to make reasonable inquiries into the sources and accuracy of data used in investment analysis. PCAOB guidance for auditors identifies source, collection conditions, controls, prior testing and diversity of sources as factors relevant to data reliability. Those principles support a simple rule: the less independent or transparent a source is, the more corroboration the number needs.
2. What date, period and scope does it cover?
Record the measurement date or reporting period, the entity or population covered, and the unit. “Revenue rose 12%” is not decision-ready until you know which company, which period, the comparison period and whether the figure is consolidated or limited to a business segment.
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Then ask whether the information is still timely for the decision. A model input may be accurate for its original time horizon but stale now. The SEC’s guidance on influential information emphasizes that published information should be timely and relevant to its audience. For a number that changes quickly—such as a share price, trading volume or forecast—check the date particularly carefully.
3. Can I tie it back to underlying records?
For company analysis, try to verify a headline figure against underlying statements or records rather than relying only on a pitch deck, article or social post. In the United States, Investor.gov directs investors to company filings and financial statements through SEC EDGAR. SEBI’s India-focused investor guidance recommends reviewing cash-flow, income and balance-sheet statements, recent prices and volumes, historical information and corporate announcements.
For India-focused company due diligence, SEBI recommends examining financial statements for at least the past two years, alongside the business, competitors, economic conditions, market data, announcements and valuation. That is India-specific investor guidance, not a universal minimum for every market or decision.
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When data feeds an analytical procedure, completeness and accuracy matter as much as the arithmetic. PCAOB guidance says auditors need support for the completeness and accuracy of data used in analytical procedures. If records are missing, inconsistent or drawn from an unexplained subset, treat the resulting number accordingly.
4. Can I reproduce the calculation and see the assumptions?
Write down the formula and inputs, including units, inclusions and exclusions. A result you cannot recreate is difficult to check, compare or explain. For a model output, identify the assumptions and time horizon, and ask what the model omits. CFA Institute guidance expects analysts to understand model assumptions and limitations and validate outputs before using them.
For an investment-performance claim, inspect the method—not just the headline return. Check how it treats fees and expenses, dividends, taxes, market conditions and the selected methodology. A return before costs and a return after costs answer different questions; make sure the figure is clear about which it represents. The SEC cautions that performance projections and back-tests are hypothetical, and that historical performance does not predict future results.
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5. Is the comparison fair?
A number can be calculated correctly and still mislead if it is compared with the wrong benchmark or a selectively chosen period. Check that the benchmark represents a comparable market segment and kind of investment. Confirm that the periods being compared include differing market conditions rather than only favorable stretches.
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6. What changes if assumptions shift or conditions worsen?
Identify the drivers that materially affect the result and test plausible adverse scenarios. If a valuation depends heavily on growth, margins, interest rates or another key input, vary that input and see how the conclusion moves. Do not treat a single base-case output as if it were certain.
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CFA Institute guidance calls for analysis of factors that substantially affect value and negative market events. It also cautions that observed databases may fail to capture both positive and negative cycles. A model that looks robust only under favorable assumptions may not be useful for a decision involving downside risk.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.7. What does not reconcile, and have I documented it?
Compare the result with an independent source or a separate expectation. Investigate material unexpected differences rather than smoothing them over. PCAOB guidance says significant unexpected differences should be evaluated, and management explanations ordinarily corroborated. A plausible verbal explanation is not a substitute for evidence.
Keep a concise record of the source, date, calculation, assumptions, checks performed, unresolved differences and remaining uncertainty. SEC guidance calls for sources, methods and assumptions to be disclosed for influential information so others can reproduce it. The same discipline makes your own reasoning easier to revisit.
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Use the checks when two claims compete
When figures disagree, compare them on the same dimensions rather than choosing the more confident presentation:
- Source: Which source is more independent, transparent and reliable?
- Date and horizon: Are the numbers current and measured over comparable periods?
- Coverage: Are the underlying data complete and accurate for the question?
- Method and costs: Do the calculations include the same items, fees and expenses?
- Benchmark and period: Is the comparison appropriate, or could period selection distort it?
- Assumptions: Does one result depend on inputs that fail under plausible adverse conditions?
Promotional material and unsolicited investment pitches should not be the sole basis for a decision. Verify both the company information and the seller independently, and do not let urgency replace these checks. Even careful diligence cannot guarantee that an investment is safe or that a figure is correct; investment decisions retain downside risk.
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