Free course · Module 7
CAPE and the Buffett indicator
Read two market valuation gauges, check what they count and understand their limits.
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Idea 1 of 4
CAPE looks through one unusual year.
CAPE means cyclically adjusted price-to-earnings ratio. It divides an index’s price by average annual earnings over the previous ten years, after adjusting those earnings for inflation. It is often called Shiller P/E.
The averaging smooths the effect of unusually strong or weak years. It does not remove uncertainty about future profits. An ordinary trailing P/E uses a much shorter earnings period; a forward P/E uses estimates. Label which measure you are reading. Source 1; Source 2.
Why adjust for inflation before averaging?
Index price ÷ ten-year average real annual earnings = CAPE.
Idea 2 of 4
A long view is different from market timing.
A valuation gauge is not a countdown to a crash. CAPE can provide context for long-horizon return assumptions. It does not supply a reliable date for the next market rise or fall. Campbell and Shiller studied valuation ratios over long historical samples; forecasts still leave substantial uncertainty. Source 2.
A low ratio is not a guarantee of gains either. Earnings definitions, industry composition, payout policies and the period selected for comparison can affect what a reading means.
How should you read historical return bands?
Valuation is context. It is not a trading clock.
Idea 3 of 4
Check what the Buffett indicator counts.
The Buffett indicator compares stock-market value with the economy’s output. In its usual form, divide the market value of listed shares by nominal annual GDP, then multiply by 100. Market value is a snapshot; GDP is production over a period. Source 3.
Different charts count different securities. One government-data proxy uses nonfinancial corporate-equity value. That narrower Fed series is not the same numerator as the total value of all listed US shares. Keep the definition attached to the result. Source 4.
Why can two websites show different readings?
Why is national GDP an imperfect comparison?
A percentage without a numerator, period and source is incomplete.
Idea 4 of 4
Try the calculations, then inspect the source.
Reproduce the arithmetic before interpreting the reading. CAPE uses index earnings; value-to-GDP uses market-value and economic-output amounts. These calculators keep the inputs separate.
Build both valuation ratios
Fixed teaching inputsFor CAPE, average and inflation-adjust the annual earnings before entering them. For value-to-GDP, use trillions of the same currency and an annual GDP measure.
CAPE
Value / GDP
Fixed examples, not live readings or forecasts. The first model does not perform inflation adjustment or gather ten years of data. Neither model recommends a trade or allocation.
Open Federal Reserve equity-value data →Use source data without turning it into a signal
Record the number, the definition and what it cannot tell you.
Quick check
Three quick checks. Feedback straight away.
How does CAPE differ from an ordinary P/E ratio?
Choose an answer to see the explanation.
For a fixed exercise, divide an index price of 1,428.68 by ten-year average real annual earnings of 32.32. What CAPE do you get?
Choose an answer to see the explanation.
Using the fixed example of $83.05 trillion of nonfinancial corporate-equity value and $32.49 trillion of annual GDP, what is the ratio?
Choose an answer to see the explanation.
Why can valuation inform a long view but fail at timing?
Review your takeaway card and the learning path
- Smooth earnings. CAPE uses a decade of inflation-adjusted annual earnings.
- Keep the long view. A valuation gauge is not a crash countdown or a return guarantee.
- Define the numerator. A nonfinancial-equity proxy differs from total listed-market value.
- Check periods and units. Record dates, revisions, definitions and unanswered questions.
Reading markers and these practice checks stay on this device. They do not mark the LMS lesson complete.
Sources and assumptions
- Robert Shiller, Online Data, Yale University. CAPE methodology and data documentation. Check the data edition and definitions.
- Campbell and Shiller, Valuation Ratios and the Long-Run Stock Market Outlook: An Update, 2001. Original research on valuation ratios and long-run market outcomes.
- CFA Institute, The Buffett Indicator Revisited, January 29, 2021. Market-cap-to-GDP definition, multinational activity, listings and comparison limits.
- Federal Reserve through FRED, Nonfinancial Corporate Equities. Series definition, units, quarterly dates and revision notice;this is a narrower numerator.
- BEA through FRED, Gross Domestic Product. Nominal GDP at a seasonally adjusted annual rate;data are revised.
All calculator and equation inputs are fixed teaching examples. They are not current market quotes or a claim about the latest GDP vintage. CAPE calculations require a consistent index series and inflation-adjusted earnings. Value-to-GDP comparisons require a defined numerator, matching units and a stated annualization convention. Local checks do not record LMS completion or grades.
StockEducation provides general education, not personal financial, tax or legal advice. Nothing here recommends a specific security. Investing involves risk, including loss of money you invest.
