Historical Indicators Point to Growing Crash Risk During Trump’s Market Rally

Key Points

• Annualized returns for the Dow, S&P 500, and Nasdaq Composite have historically outperformed under Trump compared to most presidents since the late 1890s.

• Two significant historical red flags suggest an elevated probability of a stock market crash during Trump’s presidency.

• Nevertheless, long-term historical trends have generally favored optimism over pessimism.

The Dow Jones Industrial Average (DJINDICES:^DJI), S&P 500 (SNPINDEX:^GSPC), and Nasdaq Composite (NASDAQINDEX:^IXIC) have delivered robust annualized returns under Trump, outperforming most presidents since the late 1800s. While catalysts such as artificial intelligence evolution have contributed organically, presidential policies have also played a role. The Tax Cuts and Jobs Act of December 2017 permanently reduced the peak corporate tax rate to 21%, spurring a wave of share buybacks among S&P 500 companies.

The Trump bull market may be running out of time. Image source: Official White House Photo by Daniel Torok.

With the Dow, S&P 500, and Nasdaq reaching multiple highs in 2026, investors are justified in asking whether this rally is approaching a sudden downturn.

Although past performance cannot guarantee future results, historical patterns often foreshadow market turning points. Two well-established precedents indicate that the probability of a stock market crash under President Trump is rising.

Stock valuations are a glaring red flag

At any moment, headwinds can undermine investor confidence. Few are as concerning today as stretched equity valuations.

Valuing stocks or the broader market involves inherent subjectivity, making short-term forecasting challenging. However, the S&P 500’s Shiller Price-to-Earnings Ratio, or Cyclically Adjusted P/E Ratio (CAPE), provides a standardized long-term perspective. Based on average inflation-adjusted earnings over the prior decade and backtested over nearly 156 years, the Shiller P/E offers the closest apples-to-apples comparison of the market’s benchmark index.

Stock Market Shiller PE Ratio on the verge of taking out its Dot Com Bubble all-time high pic.twitter.com/CtCmSgWnLt

— Barchart (@Barchart) July 11, 2026

Since January 1871, the S&P 500’s CAPE Ratio has averaged 17.4. As of the Aug. 28 close, it stood at 42.17, near the current bull market peak of 42.84 and approaching the all-time high of 44.19 set in December 1999.

Historically, when the Shiller P/E exceeds 30, negative outcomes follow. In nearly 156 years, the ratio has surpassed 30 on six occasions, including the present, and the previous five instances resulted in bear market declines across the Dow, S&P 500, and/or Nasdaq Composite.

While the CAPE Ratio cannot pinpoint exact timing, its record in predicting 20% or greater declines is unparalleled.

The risk-taking bubble appears ready to burst

Beyond valuations, another historical indicator points to trouble: soaring margin debt.

Margin debt represents funds borrowed from brokers to purchase or short-sell securities, effectively acting as leverage. While it can amplify gains, it also magnifies losses when positions move against investors.

Total Margin Debt hits $1.5 Trillion, a new all-time high pic.twitter.com/1IXqZGgrqs

— Barchart (@Barchart) July 20, 2026

Although margin debt typically rises with market values, parabolic growth over a short period signals danger. Outstanding margin debt surged 77% to an all-time high of $1.502 trillion over 14 months (April 2025 – June 2026), driven in part by AI-driven risk appetite.

Historically, parabolic margin spikes have preceded major bear markets. Margin debt jumped 80% over 12 months before the dot-com peak (March 1999 – March 2000), followed by a 49% S&P 500 decline and 78% Nasdaq drop. Similarly, a 66% surge over 13 months (June 2006 – July 2007) preceded the financial crisis, which erased 57% of the S&P 500’s value.

In July 2026, margin debt retreated from its $1.5 trillion peak. A sustained pullback could signal the end of the current bull market.

Image source: Getty Images.

Historical precedent is a pendulum that disproportionately favors optimists

On the surface, the data seems troubling. Elevated valuations and parabolic margin growth are historical precursors to bear markets, which can include crashes.

However, history also has a contrarian dimension.

Consider the market as a pendulum swinging between optimism and pessimism. While it may indicate growing downside risk, it does not move symmetrically. The pendulum spends a disproportionate amount of time favoring bullish outcomes.

The current bull market that began on 10/12/22 is now the 9th longest in S&P 500 history, surpassing the 1,324-day bull that ended on 2/9/1966: pic.twitter.com/4mGsS2t2ft

— Bespoke (@bespokeinvest) May 30, 2026

Bespoke Investment Group data shows the average S&P 500 bear market since the Great Depression has lasted 286 calendar days, or roughly 9.5 months, with none exceeding 630 days. In contrast, the typical bull market has endured approximately 1,023 calendar days—more than 3.6 times longer—with over half (14 of 27) lasting longer than the longest bear market on record.

While short-term doom predictions can materialize, history demonstrates that long-term optimism has consistently prevailed.

Source link