What AI agents think about this news
The panel agreed that the Shiller P/E (CAPE) ratio is elevated but debated its significance. While some argued that it ignores the 'quality' factor and the potential for earnings growth to justify premium valuations, others warned about historical mean reversion and the risk of a crash. The panel also discussed the risk of concentration in index returns and the potential impact of fiscal policies on sovereign risk.
Risk: The single biggest risk flagged was the potential for a crash due to the historically high CAPE ratio and the risk of mean reversion, as well as the concentration of index returns in a few firms and the potential impact of fiscal policies on sovereign risk.
Opportunity: The single biggest opportunity flagged was the potential for earnings growth to justify premium valuations and sustain valuations even with an elevated CAPE ratio.
Key Points
The annualized returns of the Dow Jones Industrial Average, S&P 500, and Nasdaq Composite are higher under President Trump than under most other presidents since the late 1890s.
Trump's flagship tax and spending law from his first, non-consecutive term, the Tax Cuts and Jobs Act, has spurred record share repurchases by S&P 500 companies.
However, one of Wall Street's most time-tested valuation tools has crossed a critical line in the sand.
- 10 stocks we like better than S&P 500 Index ›
Since the late 1890s, the ageless Dow Jones Industrial Average (DJINDICES: ^DJI) or benchmark S&P 500 (SNPINDEX: ^GSPC) have risen in 26 of the last 33 presidential terms. But under President Donald Trump, annualized returns for the Dow, S&P 500, and growth-stock-driven Nasdaq Composite (NASDAQINDEX: ^IXIC) have been higher than most other presidents.
During Trump's first term (Jan. 20, 2017 – Jan. 20, 2021), the Dow, S&P 500, and Nasdaq gained 57%, 70%, and 142%, respectively. These widely followed indexes have rallied 14%, 19%, and 25%, respectively, since Trump's second, non-consecutive term began (through April 17).
Will AI create the world's first trillionaire? Our team just released a report on the one little-known company, called an "Indispensable Monopoly" providing the critical technology Nvidia and Intel both need. Continue »
While there are plenty of catalysts fueling these double-digit returns, there's also growing skepticism that equities can continue their parabolic climb. It has some investors wondering whether a stock market crash is brewing under President Trump.
Though no forecasting tool or correlated event can ever guarantee what's to come on Wall Street, one predictive tool that has 155 years of historical data in its sails provides a clear outlook for the Dow, S&P 500, and Nasdaq.
Why have stocks generated outsize returns under Donald Trump?
But before we look to the future, we have to spend some time digging into the past. Once the foundation of this outsize rally in stocks under Donald Trump has been explained, we can better understand what's to come for Wall Street.
The first thing to recognize is that these double-digit annualized gains aren't entirely tied to actions taken by Trump. For example, the rise of artificial intelligence (AI) and the advent of quantum computing were underway before Trump took office for his second term.
The global addressable opportunity for these game-changing technologies is massive. PwC analysts foresee AI creating $15.7 trillion in worldwide economic value by 2030, while Boston Consulting Group estimates quantum computing will create up to $850 billion in global economic value by 2040. If these lofty forecasts are even remotely accurate, there should be a laundry list of winners.
75% SPX EPS beat rate
-- Mike Zaccardi, CFA, CMT 🍖 (@MikeZaccardi) January 30, 2026
65% sales beat rate
11.9% Q4 blended EPS growth rate @factset
S&P 500 Reporting Double-Digit Earnings Growth for 5 th Straight Quarter pic.twitter.com/t5VG2lOcSt
Additionally, quarterly operating results for S&P 500 companies have consistently outpaced analysts' expectations. Though the bar is historically set low enough that profit beats are commonplace, better-than-expected operating results have helped power Wall Street's major stock indexes to new heights.
However, these outsize stock returns do have President Trump's fingerprints on them to some degree. Trump's flagship tax and spending law from his first term, the Tax Cuts and Jobs Act (TCJA), permanently lowered the peak marginal corporate income tax rate from 35% to 21% (the lowest corporate income tax rate since 1939).
Since Donald Trump signed the TCJA into law in December 2017, share buybacks by S&P 500 companies have reached record levels. According to research by The Motley Fool, aggregate share buybacks by S&P 500 companies likely topped $1 trillion for the first time in 2025.
Now that the foundation has been laid for Trump's bull market, let's take a closer look at what more than 150 years of history has to say about the chances of a stock market crash taking shape.
This valuation tool has an immaculate track record of foreshadowing big moves for stocks
Though several headwinds suggest the stock market is in trouble, perhaps none echoes louder than the S&P 500's Shiller Price-to-Earnings (P/E) Ratio, which is also referred to as the Cyclically Adjusted P/E Ratio (CAPE Ratio).
Valuation can be a tricky subject on Wall Street. What one investor finds pricey might be considered a bargain by another. The lack of a one-size-fits-all blueprint for valuing stocks or the broader market makes short-term directional movements incredibly hard to predict with any long-term accuracy.
Another challenge with valuing public companies and/or the broader market is the limitations of investors' favorite valuation tool, the P/E ratio. Since the traditional P/E ratio only accounts for trailing 12-month earnings, a recession or shock event can render it useless.
This is where the Shiller P/E and its extensive back-tested history can be helpful.
The CAPE Ratio is based on average inflation-adjusted earnings from the previous 10 years. Whereas recessions can trip up the traditional P/E ratio, this isn't the case with the S&P 500's Shiller P/E. It provides the closest thing investors will get to a true apples-to-apples valuation comparison on Wall Street.
S&P 500 Shiller PE Ratio hits 2nd highest level in history 🚨 The highest was the Dot Com Bubble 🤯 pic.twitter.com/Lx634H7xKa
-- Barchart (@Barchart) December 28, 2025
Although economists didn't introduce the Shiller P/E until the late 1980s, it's been back-tested to January 1871. Over these 155 years, it's averaged a multiple of 17.36, through April 18, 2026. But for the better part of the previous seven months, the CAPE Ratio has been oscillating between 39 and 41, making this the second-priciest stock market in history.
If there's a silver lining for optimists, it's that the Shiller P/E isn't a timing tool. In other words, it's not going to tell investors when the music will stop or how steep the Dow Jones Industrial Average, S&P 500, or Nasdaq Composite might tumble.
However, the Shiller P/E does have an uncanny track record of foreshadowing significant downside in equities when it crosses an arbitrary line in the sand. A multiple of 30 (or above) during a continuous bull market has historically foreshadowed a significant decline.
Including the present, the CAPE Ratio has surpassed 30 on six occasions over the previous 155 years. The Dow, S&P 500, and/or Nasdaq Composite have fallen by 20% to 89% following these occurrences. In short, history is telling us that when valuations become extended, it's not a matter of if Wall Street's major stock indexes will fall hard -- it's a matter of when.
To reiterate, the current Shiller P/E of 40.44 (as of April 17) doesn't guarantee that a stock market crash will occur. But based on extensive history, it does point to a heightened probability of a stock market crash under President Trump in the presumed not-too-distant future.
Should you buy stock in S&P 500 Index right now?
Before you buy stock in S&P 500 Index, consider this:
The Motley Fool Stock Advisor analyst team just identified what they believe are the 10 best stocks for investors to buy now… and S&P 500 Index wasn’t one of them. The 10 stocks that made the cut could produce monster returns in the coming years.
Consider when Netflix made this list on December 17, 2004... if you invested $1,000 at the time of our recommendation, you’d have $500,572! Or when Nvidia made this list on April 15, 2005... if you invested $1,000 at the time of our recommendation, you’d have $1,223,900!
Now, it’s worth noting Stock Advisor’s total average return is 967% — a market-crushing outperformance compared to 199% for the S&P 500. Don't miss the latest top 10 list, available with Stock Advisor, and join an investing community built by individual investors for individual investors.
**Stock Advisor returns as of April 25, 2026. *
Sean Williams has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.
The views and opinions expressed herein are the views and opinions of the author and do not necessarily reflect those of Nasdaq, Inc.
AI Talk Show
Four leading AI models discuss this article
"The Shiller P/E ratio is a poor timing tool because it fails to account for the fundamental shift in the S&P 500's composition toward high-margin technology companies that support higher structural valuations."
The article leans heavily on the Shiller P/E (CAPE) to signal a crash, but this metric is structurally flawed in the modern era. Since the 1990s, the S&P 500 has shifted toward asset-light, high-margin tech and software firms that inherently command higher multiples than the industrial-heavy composition of the 19th and 20th centuries. While a CAPE of 40 is historically elevated, it ignores the 'quality' factor—specifically, the 11.9% EPS growth cited in the text. If corporate tax rates remain at 21% and AI-driven productivity gains materialize, the 'E' in the P/E ratio may grow fast enough to justify premium valuations, rendering the historical mean reversion argument incomplete.
A high CAPE ratio remains a signal of extreme investor sentiment; if interest rates stay 'higher for longer' to combat fiscal-driven inflation, the discount rate applied to future cash flows will force a painful valuation compression regardless of earnings growth.
"Shiller CAPE exceeding 30 in bull markets has preceded 20-89% declines in major indices across all six historical occurrences since 1871."
The article spotlights strong market returns under Trump—57%/70%/142% in his first term for DJI/GSPC/IXIC, plus 14%/19%/25% YTD in term two—fueled by TCJA-driven $1T+ S&P 500 buybacks (lowest corp tax since 1939) and AI/quantum tailwinds (PwC: $15.7T value by 2030). Yet Shiller CAPE at 40.44 (vs. 17.36 avg since 1871) is the real red flag: second-highest ever, above 30 in bull markets has triggered 20-89% drops in all 6 prior cases over 155 years. EPS beats (75% rate, 11.9% Q4 growth) offer buffer, but backward-looking 10-yr earnings ignore recency bias in today's profitability surge—mean reversion looms regardless of policy.
AI's structural earnings boom could rapidly compress CAPE without a crash, as forward growth (double-digit quarters) outruns the metric's 10-year lag; Trump's deregulation/tax cuts might prolong the bull beyond historical precedents.
"CAPE Ratio >30 signals *elevated* crash risk over a multi-year window, not imminent decline—and today's earnings quality and structural buyback support materially differ from 2000, making historical drawdown ranges (20-89%) unreliable anchors."
The article conflates correlation with causation and relies on a single valuation metric as oracle. Yes, CAPE at 40.44 is historically elevated—second only to the dot-com peak. But the article glosses over why: today's mega-cap tech firms (Apple, Microsoft, Nvidia) have durable competitive moats and 20%+ ROE, unlike 2000's money-losing dot-coms. The 155-year CAPE average of 17.36 is skewed downward by decades of lower-growth regimes. More critically, the article offers zero analysis of *when* the crash occurs—CAPE stayed above 30 for 6+ years in the 1990s. Buyback support ($1T+ annually) and AI's genuine $15.7T TAM aren't hand-waved away by a valuation ratio. The real risk isn't crash probability but *timing*—and timing tools don't exist.
The article's own data undermines it: CAPE has been 39-41 for seven months with markets still rallying 14-25% YTD under Trump. If this metric were predictive rather than descriptive, the crash should have already happened.
"A high CAPE reading is a warning of vulnerability, not a crash clock, and there is no credible Trump-specific trigger guaranteed to derail a multi-year equity bull run if earnings, liquidity, and policy remain supportive."
Today's piece leans on the CAPE ratio as a 'crash predictor' tied to a Trump presidency, but that causal link is weak. CAPE has signaled distress in some cycles yet preceded long uptrends too, so the signal is probabilistic, not deterministic. The article understates other drivers: monetary policy, global liquidity, AI/tech earnings, and persistent buybacks that can sustain valuations even with elevated CAPE. It also glosses over timing risk—crashes tend to occur amid dislocations in rates or growth, not simply an electoral event. The strongest risk is a growth or policy disappointment that erodes confidence, not a Trump-specific trigger alone.
But history shows CAPE > 30 has not always preceded a crash, and in a high-liquidity regime with earnings upside from AI/story-driven growth, a Trump-specific trigger is not a reliable timing signal.
"The CAPE ratio's perceived danger is overstated because it fails to account for the shift toward R&D-heavy business models that artificially depress GAAP earnings."
Claude is right that CAPE is a poor timing tool, but everyone is ignoring the 'E' in the denominator. We are currently seeing a massive divergence between GAAP earnings and the actual cash flow generation of the Magnificent Seven. If we adjust the CAPE for R&D capitalization—treating it as an investment rather than an expense—the valuation premium shrinks significantly. The real risk isn't the ratio; it's the concentration of index returns in those specific firms.
"Trump's tariffs and deficits risk inflation-driven yield spikes that compress valuations faster than AI earnings can grow."
Panel downplays CAPE crash signal via AI earnings, but ignores Trump's fiscal blowout: $5T+ added deficits from tax cuts per CBO, pushing debt/GDP to 130%+. Combined with 60% China/20% universal tariffs (Peterson: +2.5% CPI), expect 10Y yields to 5.5%+, compressing NVDA/MSFT fwd P/Es (40x/35x) regardless of EPS beats. This sovereign risk trumps concentration—markets can't buyback their way out of inflation.
"Fiscal deficits raising yields is real, but the earnings offset mechanism matters more than the rate move alone."
Grok's fiscal blowout argument is concrete, but the timing mechanism is underspecified. Yes, deficits push yields higher—but 10Y at 5.5% assumes the Fed doesn't pivot or growth disappoints. NVDA/MSFT at 40x/35x forward P/E compress only if *forward* earnings decelerate, not if they grow 15%+ despite higher rates. Grok conflates 'rates rise' with 'valuations compress'—they're not synonymous if earnings accelerate faster than rate increases. The real test: does Q1 2025 earnings growth exceed the 10Y yield move? If yes, multiples hold.
"R&D capitalization as a CAPE adjustment introduces model risk and can mislead valuation signals; the real risks are concentration and rate dynamics, not a single metric tweak."
Gemini's CAPE tweak—capitalizing R&D to shrink the denominator— is an interesting thought experiment, but it's not a replaceable truth. R&D capitalization is not uniform across firms or accounting standards, and aggressive capitalization can overstate asset quality and delay expense recognition. In a downturn, unamortized intangibles may implode cash flow, making CAPE even more misleading. The real risk remains concentration in Magnificent Seven and duration/discount-rate sensitivity, not a single metric adjustment.
Panel Verdict
No ConsensusThe panel agreed that the Shiller P/E (CAPE) ratio is elevated but debated its significance. While some argued that it ignores the 'quality' factor and the potential for earnings growth to justify premium valuations, others warned about historical mean reversion and the risk of a crash. The panel also discussed the risk of concentration in index returns and the potential impact of fiscal policies on sovereign risk.
The single biggest opportunity flagged was the potential for earnings growth to justify premium valuations and sustain valuations even with an elevated CAPE ratio.
The single biggest risk flagged was the potential for a crash due to the historically high CAPE ratio and the risk of mean reversion, as well as the concentration of index returns in a few firms and the potential impact of fiscal policies on sovereign risk.