U.S. stocks slumped to close sharply lower Wednesday as the Dow Jones Industrial Average sank more than 800 points and the S&P 500 had its worst day since February as technology stocks went into a freefall.

Investors spooked by rising bond yields dumped equities in all sectors, triggering a broad market rout.

The Dow Jones Industrial Average DJIA, +0.19% skidded 831.83 points, or 3.2%, to 25,598.74, logging its worst one-day drop since February.

The S&P 500 index SPX, +0.29% lost 94.66 points, or 3.3%, to 2,785.68, falling for its fifth straight day, the longest losing streak since November 2016. The large-cap index’s losses were topped by the technology sector, which slid 4.8%, the steepest percentage drop since August 2011.

The Nasdaq Composite Index COMP, +0.36% fell 315.97 points, or 4.1%, to 7,422.05, its biggest decline of 2018.

The Russell 2000 RUT, +0.02% , an index for small-capitalization stocks, sank 2.9% to 1,575.41.

What drove the market?

Market action has been adversely affected by higher bond yields and interest rates, both of which could signal a new phase in postcrisis markets that have enjoyed a protracted period of ultralow yields.

A rise in yields results in steeper borrowing costs for corporations and investors, and has caused a reassessment of equity valuations, already deemed lofty by some measures. On top of that, richer rates of so-called risk-free bonds can attract investors away from equities, which are perceived as comparatively riskier. However, rising yields are also seen as a reflection of a strong economy, one that has been supported by a number of strong economic data points.

On Wednesday, the yield on the U.S. 10-year Treasury note TMUBMUSD10Y, 0.669% eased slightly after rising to 3.23%.

Traders were also looking ahead to the start of the third-quarter earnings season, which unofficially begins later this week with results from major financial institutions. Broadly speaking, earnings growth is expected to be strong, which could provide an underpinning to equity prices, although there have been some concerns that expectations are too high, which could lead to disappointments.

Read: Barclays outlook on earnings sends internet company shares tumbling

In the latest economic data, the producer-price index rose 0.2% in September, while the core PPI was up 0.4%. Separately, wholesale inventories in the U.S. rose 1% in August.

Late Tuesday, Dallas Federal Reserve President Rob Kaplan said he sees some inflationary pressures building, but that he doesn’t think there will be a sudden spike in prices. He also said he sees a risk of higher oil prices in coming years.

President Donald Trump on Tuesday had repeated his criticism of Fed policy, saying the central bank doesn’t have “to go as fast” with raising interest rates. The Fed has raised rates three times this year and it has indicated it would do so again in December.

In the latest on the trade-policy front, U.S. Treasury Secretary Steven Mnuchin warned Beijing against engaging in a competitive devaluation of the yuan, though he stopped short of accusing China of purposely weakening its currency.

What were analysts saying?

“Sentiment is mixed, spurred by rising interest rates and a general heightened degree of investment difficulty,” said Terry Sandven, chief equity strategist at U.S. Bank Wealth Management. “Bonds matter, trade policy remains a work in progress and the midterm elections are less than one month away. As interest rates trend higher, bonds become a more viable alternative to equities and valuation multiples tend to become compressed.”

“In the short term, U.S. equity markets are becoming oversold and due for a rebound as the S&P tests first support at its 50-day moving average, the Nasdaq is at its 100-day moving average and the Russell 2000 is at its 200-day moving average at 1,600 support. An oversold rally is likely to develop in the coming few days,” said Robert Sluymer, technical strategist at Fundstrat Global Advisors.

Brad McMillan, chief investment officer at Commonwealth Financial Network, characterized the market’s decline as “normal volatility” and said stocks were “past due for a pullback.”

“My take on the immediate cause is interest rates. When rates spike like they have, some reaction is unavoidable. Treasury rates are the foundation of valuation in all financial assets, and when they go up it will shake everything,” he said in a note to clients.

The point where investors should start paying attention is when the S&P 500 dips below its 200-day moving average of 2,765, according to McMillan.

What stocks were in focus?

Starbucks Corp. SBUX, +0.06% shares fell 3% after Bill Ackman revealed his hedge fund, Pershing Square Capital Management LP, has built a roughly 1.1% stake in the coffee giant.

Myriad Genetics Inc. MYGN, +0.41% shares rose 3.9% after it announced an agreement to carry out testing for Pfizer Inc. PFE, -0.66%

Imperva Inc. US:IMPV soared 28% after it announced it would be acquired by private-equity firm Thoma Bravo LLC in a deal valued at $2.1 billion.

Sears Holdings Corp. US:SHLD skidded 17% to 49 cents after the Wall Street Journal reported that the troubled retailer has hired M-III Partners LLC to prepare a bankruptcy filing that could come as soon as this week.

Shares of Papa John’s International Inc. PZZA, -4.02% shed 1.6%. Kalinowski Equity Research projected that the pizza chain will probably be bought out in the next year.

U.S.-listed shares of Nio Inc. NIO, -0.61% rose 4.9% after news that Baillie Gifford & Co., a major Tesla Inc. TSLA, +1.95% shareholder, has taken an 11.44% stake in the Chinese electric-car maker. In contrast, shares of Tesla declined 2.3%.

Twitter Inc. TWTR, -4.83% slumped 8.5% after a Barclays analyst projected the social-media company’s third-quarter earnings to be “washed out.”

What did other markets do?

Asian markets were mixed, with Chinese shares trading slightly higher. Most major European indexes trended lower.

Oil prices US:CLK9 declined amid signs that Iran crude exports are falling ahead of reimposed sanctions. Investors were also monitoring any risks to energy infrastructure as Hurricane Michael battered Florida’s Panhandle.