How do I check a number before I make an investment decision? I use seven checks: trace its source, confirm its date and scope, tie it to underlying records, reproduce the calculation, judge the comparison, test what changes under worse conditions, and investigate anything that does not reconcile. This is a practical diligence routine—not a guarantee that a figure is correct or an investment is safe.
1. Where did the number come from?
Trace the figure to its originating document or data provider rather than stopping at a chart, social post, pitch deck, or article repeating it. Find out who collected the information, how it was collected, and whether the source is independent of the person presenting the claim. A company filing and a promoter’s summary may describe the same figure, but they do not provide the same degree of distance from the claim.
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CFA Institute guidance says members and candidates should make reasonable inquiries into the sources and accuracy of data used in investment analysis. PCAOB guidance for auditors also identifies source, collection conditions, controls, prior testing, and diversity of sources as factors in evaluating information reliability. These are useful diligence principles, not a universal legal checklist.
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2. What date, period, and scope does it cover?
Record when the number was measured, the period it covers, and exactly which company, asset, market, or population it describes. A quarterly result, a point-in-time price, and a multi-year average answer different questions. Check whether the information is still timely for the decision, and whether its scope matches the claim being made.
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For model inputs, CFA Institute highlights the importance of understanding the source and time horizon. SEC guidance likewise says published information should be timely and relevant to its audience. A correct figure can still mislead if it is stale or presented as applying to a broader group or period than it actually covers.
3. Can I tie it to underlying records?
Where available, follow the number back to filings, financial statements, or other supporting records. Investor.gov directs investors to company filings and financial statements through SEC EDGAR. For India-focused company diligence, SEBI recommends reviewing cash flow, income, and balance sheet statements, alongside recent prices and volumes, historical data, and corporate announcements.
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For data used in analytical procedures, PCAOB guidance calls for support for its completeness and accuracy. If you cannot establish what records the figure came from—or what may have been left out—treat it as an unresolved limitation rather than verified fact.
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Write down the formula and inputs, including units, inclusions, and exclusions. If the figure is a performance claim, check how it treats fees and expenses, dividends, taxes, market conditions, and the calculation methodology. Two reported returns may not be comparable if one includes costs or reinvested dividends and the other does not.
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CFA Institute guidance expects analysts to understand model assumptions and limitations and to validate model outputs before using them. A model result is only as decision-useful as its data, assumptions, time horizon, and validation. For projections and back-tests, keep in mind that they are hypothetical; historical performance does not predict future results.
5. Is the comparison fair?
Check whether the benchmark represents the same market segment and kind of investment as the figure being assessed. Then inspect the selected period: does it include different market conditions, or only a favorable window? The SEC warns that benchmark returns may omit investor fees and describes cherry-picking as presenting good periods while excluding bad ones.
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When two numbers or claims compete, compare them on the same basis: source independence and reliability, date and horizon, completeness and accuracy, calculation method and costs, benchmark and period, and sensitivity to assumptions or adverse scenarios.
6. What changes if assumptions shift or conditions worsen?
Identify the drivers that materially affect the result, then test how it responds to plausible downside scenarios. Ask which inputs matter most, how much they would need to move to change the conclusion, and whether a negative market event would make the estimate unusable.
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CFA Institute guidance calls for analyzing factors that substantially affect value and negative market events. It also cautions that observed databases may not capture both positive and negative cycles. A favorable model output is not a substitute for checking how it behaves outside the conditions that produced it.
7. What does not reconcile, and what evidence supports the explanation?
Compare the result with a separate expectation or source. If the gap is material or unexpected, investigate it rather than smoothing it over with a plausible-sounding explanation. PCAOB guidance says significant unexpected differences should be evaluated and management explanations ordinarily corroborated. Keep a record of the evidence, the explanation, and any uncertainty that remains.
The SEC calls for sources, methods, and assumptions to be disclosed for influential information so others can reproduce it. Documentation makes it possible to revisit the judgment later and distinguish a supported conclusion from an unresolved discrepancy.
When a pitch or company claim needs extra caution
Promotional material and unsolicited investment pitches should not be the sole basis for a decision. Verify the company information and the seller independently, and resist pressure to act urgently. For India-focused investor due diligence, SEBI recommends reviewing a company’s financial statements for at least the past two years, together with its business, competitors, economic conditions, market data, announcements, and valuation. That is SEBI guidance for its investor context, not a universal minimum for every investor or jurisdiction.
What this routine can—and cannot—establish
CFA Institute, SEC, SEBI, and PCAOB guidance supports habits behind this routine, but none publishes this exact seven-check list. Their rules and guidance apply in their respective contexts: CFA Institute guidance to members and candidates, PCAOB requirements to auditors within its remit, and SEBI investor guidance in India. The checks help expose weak sourcing, mismatched periods, opaque calculations, unfair comparisons, and unexplained differences; they cannot remove investment risk or guarantee that a number is right. CFA Institute also notes that downside risk remains even after a diligent recommendation.
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