NEW YORK — Nov. 1, 2026 — Octoberphobia is returning to Wall Street after artificial intelligence and semiconductor stocks lost approximately $5 trillion in market value during October. This is  raising concerns about whether the technology sector is entering a deeper correction.

However, historical market patterns suggest the latest sell-off could also set the stage for a potentially stronger period for stocks as investors enter November and the final months of 2026.

The latest decline has exposed a growing divide between technology stocks and the broader U.S. equity market. While dozens of major AI and semiconductor companies experienced significant losses, hundreds of other large American companies posted gains. The clear suggestion is that the weakness has not affected every part of the market equally.

Jeff Hirsch, editor of the Stock Trader's Almanac, describes the tendency of investors to fear October market declines as "Octoberphobia." Rather than viewing the latest losses as a reason to abandon stocks, Hirsch believes the pullback could create buying opportunities."I did buy some today... this is an opportunity here."

Hirsch told Yahoo Finance on Friday. He added that the damage was not as severe as the headlines suggested. His optimism is based partly on historical market performance, particularly the tendency for stocks to strengthen following midterm election years.

AI and Semiconductor Stocks Lose Trillions During Octoberphobia

The latest October sell-off has been particularly severe for companies associated with artificial intelligence and semiconductor manufacturing.

According to Yahoo Finance calculations, approximately 47 AI and chip-related stocks lost a combined $5 trillion in market value between Oct. 6 and the end of the month.

Nvidia and Alphabet each lost approximately $835 billion in market capitalization during the period. Intel also experienced a significant decline, losing nearly half its market value in October.Other companies, including SpaceX and Taiwan Semiconductor Manufacturing Co., also experienced substantial losses.

However, the broader market demonstrated considerably more resilience.The other 625 large U.S. stocks included in Yahoo Finance's analysis collectively added approximately $1.3 trillion in market value.

The S&P 500 also showed signs of underlying strength despite weakness among some of its largest technology constituents. Nine of the index's 11 sectors gained approximately 1% or more during the latest week. Yahoo Finance said this had not occurred in any week since at least 1999.

The divergence suggests investors may be moving money away from some heavily valued technology companies and toward other areas of the economy.

For Wall Street, the question is whether the AI sell-off represents a temporary adjustment in valuations or the beginning of a more prolonged decline.

Why October Has a Reputation for Stock Market Crashes

October has a long history of dramatic stock market declines, earning a reputation as one of Wall Street's most psychologically difficult months. Several major financial disasters have occurred during October, reinforcing investors' tendency to associate the month with market instability.

The 1929 Stock Market Crash was one of the most infamous examples. It occurred  when a wave of panic selling devastated the U.S. stock market.

On Oct. 24, known as Black Thursday, investors rushed to sell shares amid growing concerns about speculative valuations and economic conditions. The panic intensified on Oct. 28 and Oct. 29, when the market experienced additional devastating losses.

The crash helped usher in the Great Depression, although the economic downturn had multiple contributing causes and continued long after the initial market collapse. The Dow Jones Industrial Average eventually lost nearly 90% of its value from its 1929 peak to its 1932 low.

The experience established October as a month associated with some of the most painful moments in American financial history.

Black Monday in 1987

Another major October disaster occurred on Oct. 19, 1987.Known as Black Monday, the Dow Jones Industrial Average plunged approximately 22.6% in a single trading session. This marked its largest one-day percentage decline.

The crash was associated with several factors, including concerns about economic conditions, rising interest rates, computerized trading strategies and portfolio insurance.The speed and severity of the decline shocked investors around the world. Despite the dramatic collapse, U.S. markets eventually recovered, demonstrating that even extraordinary market losses do not necessarily result in permanent declines.

The 2008 Financial Crisis

October 2008 delivered another devastating period for investors as the global financial crisis intensified. Following the collapse of Lehman Brothers in September, financial institutions faced mounting pressure, credit markets tightened. Investors rushed to reduce exposure to risky assets. The S&P 500 suffered a substantial monthly decline in October 2008 as fears of a prolonged economic contraction spread.

The crisis eventually resulted in a deep recession, government intervention and significant changes to financial regulation.Unlike a temporary correction, the 2008 downturn reflected serious problems throughout the banking system and broader economy.These historical episodes help explain why October declines can trigger emotional reactions among investors even when the underlying economic circumstances differ substantially.

Octoberphobia May Indicate Sell-Offs 

Although October has been associated with major financial disasters, it has also produced recoveries and strong market performances.The month itself does not determine whether stocks will rise or fall in the months ahead.

Investors who automatically sell during October declines risk missing subsequent recoveries. Hirsch believes the latest market weakness should be considered in the context of historical seasonal patterns rather than viewed in isolation.

His research focuses particularly on the presidential election cycle and the period following midterm elections. According to the Stock Trader's Almanac data cited by Yahoo Finance, the S&P 500 has finished higher in all 19 midterm-year October-to-following-June periods since 1950.

The median gain during those periods was approximately 15%.Semiconductor stocks have demonstrated a similar pattern.The sector finished higher by the following June in all eight midterm-year cycles since 1994, with a median gain of approximately 22%.However, historical performance does not guarantee future results, and the semiconductor sample is relatively small.

Why November Is Historically Important for Investors

November has traditionally been one of the strongest months of the year for the U.S. stock market.Historical market data frequently place November near the top of the calendar-year performance rankings for the S&P 500.

The broader November-through-April period has also historically produced stronger average stock market returns than the May-through-October period. This pattern is sometimes described as the market's best six months.

Several factors can contribute to seasonal strength, including institutional portfolio adjustments, improving investor sentiment and expectations surrounding holiday spending.

The post-midterm election period has also historically been favorable for stocks.Hirsch believes these patterns could provide support for the market following October's technology-sector sell-off.However, investors should remember that seasonal trends are historical observations rather than reliable short-term trading signals.

Economic conditions, interest rates, corporate earnings and geopolitical developments can outweigh seasonal tendencies.

Semiconductor Stocks Face Tests and a Possible "Bear Trap"

The iShares Semiconductor ETF (SOXX) experienced a particularly difficult October, falling approximately 17% during the month. Despite that decline, the fund remained more than 50% higher for the year, illustrating how strong earlier gains had been.

On Friday, SOXX briefly dropped to approximately $460, falling below its July 29 low near $464.The fund subsequently recovered and closed near $472, moving back above the earlier support level.

Technical analysts sometimes describe this pattern as a bear trap, which occurs when a security briefly falls below an important support level before recovering. Such movements can catch investors who have positioned themselves for additional declines. Hirsch considers the recovery encouraging and believes semiconductor stocks could benefit from the historically favorable seasonal period ahead.

However, several technical levels remain important.A recovery above approximately $524 would represent an initial improvement, while the early-October high near $596 could become another important level to watch.If SOXX falls decisively below its July low, investors could begin watching the February-to-April trading range near $370.

That would represent a potential decline of approximately 21% from Friday's closing price.These levels are technical reference points, not guaranteed price targets.

Not Everyone on Wall Street Is Buying the Dip

Despite Hirsch's optimism, other market observers remain concerned about the financial environment.Bank of America's Michael Hartnett has maintained a more cautious position. He argues that investors should remain risk-averse until the global cycle of interest rate increases ends.

Hartnett pointed to 42 central bank rate increases worldwide during the preceding six months.

The Federal Reserve held interest rates steady at its latest meeting, although two officials voted in favor of an increase. Hartnett has identified approximately $520 on the VanEck Semiconductor ETF (SMH) as an important level for semiconductor investors.

The fund closed Friday near $522, leaving it close to that threshold.The competing assessments highlight the uncertainty facing investors. Hirsch sees the October decline as a potential opportunity supported by favorable seasonal patterns.

Hartnett's position reflects concerns about monetary policy, global interest rates and the possibility that financial conditions could remain restrictive.Both perspectives underscore the importance of watching market performance rather than assuming that a historical pattern will repeat.

The S&P 500's Next Major Test

The broader stock market is also approaching an important technical threshold. Hirsch said a decisive decline below the S&P 500's mid-September low near 7,550 would cause him to reconsider his optimistic assessment.

That level is less than 1% below Friday's closing price, placing the market relatively close to an important point in his analysis.The upcoming midterm election could also influence investor sentiment.

Historically, markets have often performed well during the period following midterm elections, although political developments and economic conditions can produce different results in individual years.Investors will also be watching corporate earnings, Federal Reserve policy, inflation data and the financial performance of major technology companies.

Will Octoberphobia Give Way to a November Rally?

The $5 trillion decline in AI and semiconductor market value has raised legitimate questions about the sustainability of the technology investment boom.However, the broader market's resilience suggests that the October losses have not necessarily translated into a widespread retreat from American equities.

Historical evidence provides reasons for investors to monitor the coming months closely.The S&P 500's record across previous midterm election cycles, combined with November's historically strong performance, has encouraged some market strategists to look beyond October's volatility. Still, the historical record does not eliminate the possibility of further losses.

Investors must weigh the potential benefits of seasonal strength against concerns about interest rates, technology valuations, corporate earnings and the financial health of companies heavily invested in artificial intelligence.

For Hirsch, the latest decline represents an opportunity rather than a reason to panic.For more cautious investors, the next several weeks could provide important clues about whether the market is stabilizing or preparing for another downturn.As Wall Street enters November, the central question is whether Octoberphobia will prove to be another temporary bout of market anxiety or an early warning of deeper financial trouble.

Additional information and Sources

The following sources provide historical market data, background on October crashes and information about the current market environment.

1. Yahoo Finance: AI Stocks Just Lost $5 Trillion — But History Says the Stock Market's Sweetest Stretch Starts Now 

2. Stock Trader's Almanac — Historical Market Seasonality 

3. Federal Reserve History: The Great Depression 

4. Federal Reserve History: The Stock Market Crash of 1987 

5. Federal Reserve History: The Financial Crisis of 2007-2009 

6. S&P Dow Jones Indices 

7. iShares Semiconductor ETF (SOXX) 

8. VanEck Semiconductor ETF (SMH) 

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