MarketGPS

CAPE Boom & Bust Cycles

Market Signal

Current Stock Prices

Status

High Risk

Current Shiller PE

CAPE Ratio

41.52
Strong Sell

As of Sep 21, 2026

Deviation

+134%vs 17.75 mean

CAPE Risk Range

Velocity Indicator

Strong BuyStrong Sell

Risk Level

Extreme

134% Valuation Gap

Mean vs Current Comparison

Risk Projection

Extreme valuations do not predict when a market turns. They have been remarkably consistent about how much is given back when it does.

3 of 3

Times CAPE Crossed 40

In 1929, 2000, and 2021, every prior crossing of this threshold was followed by a decline of 25% to 49%. Three for three in 156 years. CAPE has never told anyone the date — only the distance.

Risk Recommendation

Extreme risk protocol active

Primary Action

Move To Cash

Secondary Directive

Lock In Retirement Income

System Status

Capital Preservation Mode

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Historic Boom & Bust Cycles

The Trillions Trifecta

The Market Distortion Loop

  1. 01

    Government Policy & QE

    De-risks tech manufacturing and injects liquidity through regulatory shields and security mandates.

  2. 02

    AI Expansion Hype

    Drives hyper-growth narratives and investor euphoria, pushing valuations away from underlying earnings.

  3. 03

    Data Centre Infrastructure

    A physical buildout consuming capex, energy and chips — funnelling capital back into the market’s largest stocks.

The Result

“An unusual alignment of national security policy, corporate capital spending, and technology narrative — all pushing the same handful of prices in the same direction.”

Historical Crash Comparison

Every cycle where CAPE closed above 40.0

3 Occurrences Detected
Historical episodes where the Shiller CAPE ratio exceeded 40
Bubble EraPeak Shiller P/ESubsequent DeclineRecovery DurationStatus
Dot-com Bubble (2000)44.19−49%7.2 YearsRegressed
Post-Pandemic Peak (2021)40.0+−25%2.1 YearsRegressed
Current Active Cycle (2026)41.52In ProgressActiveCritical Alert

Market Education

5 Reasons You Should Care About The Shiller CAPE Ratio

  1. The Ultimate Valuation Compass

    Introduced in 1988 by economists Robert Shiller and John Campbell, the Cyclically Adjusted Price-to-Earnings ratio smooths ten years of inflation-adjusted earnings to show whether stocks are cheap or dangerously expensive — without the distortion a single bad quarter creates.

  2. Built On 150 Years Of History

    CAPE is trusted because it neutralizes short-term noise across a dataset stretching back to 1871. It has been measured through the Panic of 1873, the Great Depression, two world wars, stagflation, and every bubble since.

  3. The Danger Zone Threshold

    A CAPE above 40 has always signalled extreme overvaluation. It does not tell you when the market turns. It has been remarkably consistent about how far it falls when it does.

  4. A Rare Precedent

    CAPE has crossed 40 in only three episodes in 156 years. In the two that have already resolved, the market gave back between 25% and 49% — and took between 2 and 7 years to recover.

  5. Extreme Historical Deviation

    The long-run average since 1881 is 17.75. Every point above that is a claim about future earnings that has to come true for today’s price to make sense.