CAPE Ratio Explained: When Is the S&P 500 Actually Expensive?

April 7, 2026 · Stock Analysis · 9 min read

Every year someone publishes an article titled "The S&P 500 is at an All-Time High. Is It a Bubble?"

The answer is usually: "Maybe. Here's a P/E ratio." But the P/E ratio tells you almost nothing about whether the market is actually expensive, because current earnings are often at cyclical peaks or troughs.

That's why investors use the CAPE ratio — short for Cyclically Adjusted Price-to-Earnings. It smooths out the noise in a single year's earnings and answers a different question: "Relative to 10-year average earnings, how expensive is the market?"

This guide walks through how CAPE works, what it tells you, and what it doesn't — including how to apply it to individual stock picking, not just broad market assessment.

What Is the CAPE Ratio?

The CAPE ratio is the S&P 500 price divided by the average inflation-adjusted earnings of the previous 10 years.

CAPE = Current S&P 500 Price / (Average inflation-adjusted earnings over last 10 years)

Currently, the S&P 500 is trading at a CAPE of roughly 38–40x, depending on the source and calculation methodology. For reference:

CAPE < 20: Historically cheap. Corresponds to periods of significant market weakness or early recovery.
CAPE 20–25: Fair value. Corresponds to the long-term average.
CAPE 25–30: Moderately expensive. Elevated but not extreme.
CAPE 30–35: Expensive. Above long-term average, suggests caution.
CAPE 35+: Very expensive. Suggests either exceptional growth expectations or genuine overvaluation.

The current 38–40x is in "very expensive" territory, comparable to 1929 (before the crash), 2000 (before the tech bubble burst), and the COVID recovery peak in 2021.

Why CAPE Matters More Than the P/E Ratio

The traditional P/E ratio (Price divided by current year earnings) has a critical flaw: it uses current year earnings, which can be distorted by the business cycle.

Consider two scenarios:

Scenario 1: 2008 (Financial Crisis)

S&P 500 price: $800
2008 earnings: $50 (depressed by recession)
P/E ratio: 800/50 = 16x (looks cheap!)
10-year average earnings: $80 (normal, not crisis-depressed)
CAPE ratio: 800/80 = 10x (actually extremely cheap)

The P/E ratio was misleading. The CAPE showed the market was genuinely a screaming bargain.

Scenario 2: 2021 (Post-COVID Recovery)

S&P 500 price: $4,600
2021 earnings: $220 (boosted by strong recovery and stimulus)
P/E ratio: 4,600/220 = 21x (looks reasonable)
10-year average earnings: $140 (includes 2008-2012 recession recovery years)
CAPE ratio: 4,600/140 = 33x (expensive by historical standards)

Again, the traditional P/E was masking the truth. CAPE showed the market was trading at a significant premium to historical norms.

What a High CAPE Ratio Actually Means

A CAPE of 38x doesn't mean the market is going to crash. It means one of three things:

1. Earnings are genuinely compressed relative to future potential.

If the 10-year average includes 2020 (recession year) and 2021–2024 (strong recovery), the average can be artificially low compared to the forward run-rate.

This happens in markets after major disruptions. The 10-year average includes crisis years. As those years age out of the calculation, CAPE will naturally decline even if prices stay flat.

Example: In 2024, the CAPE calculation includes 2014–2023. 2014–2019 were below-average years for tech earnings (cloud adoption), and 2020 was a crisis year. By 2025–2026, the 10-year window shifts to 2015–2024 — pulling in the stronger growth years of 2022–2024 and dropping the pandemic year. CAPE can decline meaningfully without the market falling.

2. The market is genuinely expensive.

Sometimes a high CAPE reflects the market pricing in structural changes and superior future growth.

The 2010s (post-financial-crisis) had a high CAPE for most of the decade — not because the market was in a bubble, but because investors were repricing the market for lower interest rates, quantitative easing, and the internet's structural growth advantages.

Those growth expectations were largely realized.

3. The market is in a speculative bubble.

And sometimes high CAPE precedes crashes. In 2000, the CAPE hit 44x before the tech bubble burst. In 1929, it hit 32x before the crash.

The problem: CAPE is good at identifying overvalued periods. It's bad at timing crashes. The market stayed expensive for years (or decades) before correcting.

CAPE's Strength and Weakness

Strength: Long-term Return Predictor

CAPE has a measurable correlation with subsequent 10-year returns. High CAPE periods have historically corresponded to lower forward returns. Low CAPE periods have corresponded to higher forward returns.

The correlation isn't perfect, but it's significant. On average:

CAPE < 15: Subsequent 10-year annualized return ~11%
CAPE 15–25: Subsequent 10-year annualized return ~8%
CAPE > 25: Subsequent 10-year annualized return ~5%

This is why value investors watch CAPE — it's a signal of long-term expected returns, not near-term price direction.

Weakness: It Doesn't Tell You When

The biggest weakness of CAPE is that it's backwards-looking. It tells you the market is expensive, but not whether expensive means "slightly overvalued and will correct in 3 months" or "moderately overvalued and will compound returns at 4% for 5 years."

A CAPE of 35x in 2013 correctly signaled elevated valuations. But the market returned 300%+ from 2013 to 2021. An investor who avoided stocks based on a high CAPE would have missed a decade of gains.

High CAPE is a headwind to future returns, not a crash signal.

What About Individual Stocks?

CAPE is a broad market metric. But the same principle applies to individual stocks — be cautious about holding large portions of wealth in stocks trading at 10-year average P/E ratios significantly above sector norms.

Use the individual stock version of this logic:

Fair value via 10-year P/E average: What is the stock's normal P/E (price divided by 10-year average earnings)?
Current P/E: What is it trading at today?
Valuation gap: Is the current P/E 20% above the 10-year average? 50%? 100%?

Stocks trading 30%+ above their 10-year average P/E in sectors where that's normal (like technology) may be fairly valued. Stocks trading 50%+ above 10-year average in defensive sectors (utilities, consumer staples) are likely expensive and merit closer scrutiny.

Equity Rank's screener uses a blended approach: fair value via eight methods, not just historical P/E. This accounts for structural changes in a business (e.g., a tech company transitioning from growth to profitability) that CAPE would miss.

CAPE and Current Market Conditions (2026)

The S&P 500 is at a CAPE of ~38–40x, among the highest in history. What does this mean for your portfolio?

For long-term buy-and-hold investors:

High CAPE suggests lower forward returns over the next 10 years. Instead of 8–10% annualized, expect 4–6%.
It's a reason to be more selective about stock picking — in a low-return environment, the difference between owning high-quality stocks at fair value versus overpaying for mediocre stocks matters more.

For tactical traders:

High CAPE suggests the market is vulnerable to drawdowns. Not imminent crashes, but higher volatility and worse risk-adjusted returns.
A 20–30% market correction is more likely in a 38x CAPE environment than a 18x CAPE environment.

For stock pickers:

High CAPE doesn't mean all stocks are expensive. It means the average is expensive. Plenty of undervalued stocks exist even in expensive markets.
Use Equity Rank to find stocks with strong margins of safety, regardless of overall market CAPE.

Key Takeaways

CAPE smooths out earnings cycles. It uses 10-year average earnings instead of current earnings, filtering out the noise of recessions and booms.
Current CAPE (38–40x) is expensive by historical standards. Comparable to 2000 and 1929, suggesting caution but not guaranteed imminent correction.
High CAPE predicts lower forward returns, not timing. Historically, high CAPE periods return 4–6% annualized over 10 years, not 8–10%.
CAPE is a long-term signal, not a crash timer. Markets have stayed expensive (or cheap) for years. Don't use CAPE alone to time entries and exits.
In expensive markets, stock selection matters more. When the market is trading at 38x, the difference between owning fair-value stocks and overpaid stocks is compounded over decades.
Individual stocks can be cheap even in an expensive market. Use Equity Rank to identify stocks with strong margins of safety regardless of overall market valuation.

For informational purposes only. Not financial advice. Historical CAPE correlations do not guarantee future results. Market valuations change based on interest rates, growth expectations, and investor sentiment. Actual forward returns may vary significantly from historical averages. Equity Rank is not a registered investment adviser. Consult a qualified financial adviser before making investment decisions.