NEW YORK – The world’s largest technology companies drove the stock market to record highs earlier this year. As stocks have tumbled, though, it is more like they are just along for the ride.

Unlike the rally, the rout that started in late September and dominated trading in October was a broad-based affair. That suggests that investors are less concerned that the tech giants’ shares rose too far too fast, and are instead worried about the fundamentals of the U.S. economy and the continuing profitability of companies of all kinds.

October was particularly painful for investors. At its worst, the S&P 500 index was down more than 9 percent during the month. A late charge took some of the sharp edge off: The S&P 500 was up around 1 percent on Wednesday, its second straight gain, helping to cut losses for the month to around 7 percent.

“I think there’s something that’s bothering the markets, and I think it’s fears about earnings estimates,” said Randy Watts, chief investment strategist with the investment advisory firm William O’Neil & Co.


How WRAL TechWire’s 30 index performed in October. It includes many major tech stocks. Get more information at:

After nearly a decadelong bull market, investors have been increasingly skittish about how long the push higher could extend. And sweeping declines like the one that roiled stocks during October have prompted some to consider whether the rally that began in March 2009 is indeed under threat.

The S&P 500 topped out on Sept. 20, up 9.6 percent for the year, and nearly half of the increase was fed by the performance of five huge tech companies: Apple, Amazon, Microsoft, Netflix and Google’s parent company, Alphabet.

But in the weeks since that peak, the gains experienced by the benchmark stock index over the previous nine months were largely wiped out.

And only about 20 percent of the slump can be tied to the tech giants, compared with the 50 percent of the gain they were responsible for earlier in the year.

The S&P 500 has been dragged down disproportionately by smaller, domestically focused companies, cyclically sensitive industrial firms and global manufacturers like Caterpillar. And companies like the fertilizer and chemical giant DowDupont and the home-improvements retailer Home Depot have pulled the S&P 500 down by more than they ought to, based on their size.

There are plenty of factors that worry investors: President Donald Trump’s trade war with China; the Federal Reserve’s stated plans to keep raising interest rates; signs that labor and other costs could climb; and slowing growth in Europe and China. And the tax cuts that increased growth in profits this year will not have the same year-over-year effect in 2019.

Chemical and materials companies have experienced steep declines faced with mounting concerns over global trade. DowDupont is still waiting for Beijing to approve one of its bioengineered soybeans to be imported into China, the world’s largest soybean market. The approval process may be more complicated now that soybean exports from the United States to China are subject to a 25 percent tariff imposed by Beijing over the summer in response to Trump’s tariffs on Chinese-made goods.

DowDupont is only the 39th largest company in the S&P 500, but its nearly 16 percent drop in October made it among the larger contributors to the index’s downturn, according to the market data firm FactSet.

Home Depot is the 23rd largest company in the S&P 500, but it played the ninth-largest role in the October sell-off through Monday. Its shares were down about 15 percent in October as climbing interest rates slowed the housing market, a key factor in home improvement spending.

Bank of America, JPMorgan Chase, Mastercard and Visa — financial firms whose fortunes are closely linked to the economy’s overall health and sensitive to rising interest rates — have also helped pull down the market.

“Despite the fact that earnings are exceptional by any objective measure, investors are concerned that they will slow more dramatically than expected next year,” said Jason DeSena Trennert, managing partner at Strategas Research Partners, a markets and economic analysis firm.

The biggest tech firms have played a part in the broad decline, of course. The stock market bench marks, such as the S&P 500, are weighted by market value, meaning the vast size of Apple, Amazon, Alphabet and Microsoft give them significant influence over how the index moves.

Amazon’s 20 percent drop in October — much of it coming after an earnings report that contained a disappointing outlook for the holiday season — helped make it the single biggest drag on the S&P 500 during the recent sell-off.

The software giant Microsoft dropped more than 6 percent in October. Alphabet fell around 9 percent. Facebook was down more than 7 percent for the month after rebounding on Wednesday upon the release of the company’s quarterly earnings report.

The only big tech company left to report for the quarter is Apple, which is expected to release its results Thursday. The company’s stock price was off about 3 percent in October, faring far better than the overall market.

The tech companies’ declines are not minor, but they are not big enough to signal that investors are overly concerned about the health of the stocks that have fueled so much of the gains of the past decade. Even with companies like Amazon, Microsoft and Alphabet having outsize sway over market bench marks, the losses felt in other sectors suggest that when it comes to the falling indexes, the tech giants’ tumbles are more of a symptom than a cause.