U.S. stocks sold off for a second straight session on Tuesday, with the Dow suffering its biggest one-day drop in eight months, as heavy losses in health-care and energy shares weighed on the main indexes.

The Dow Jones Industrial Average was down as much as 400 points after Amazon, Berkshire Hathaway and JPMorgan Chase announced they would partner in an effort to cut health-care costs and improve services for U.S. employees. The announcement sent shares of several health-care companies sharply lower.

Meanwhile, climbing U.S. bond yields, which imply a rise in borrowing costs, were also weighing on stocks in a repeat of Monday’s action.

Investors are looking ahead to the State of the Union address by President Donald Trump, while a busy day for corporate earnings saw results from big names such as McDonalds Corp. and Pfizer Inc.

What did stocks do?

The Dow Jones Industrial Average DJIA, -0.87% dropped 362.59 points, or 1.4%, to 26,076.89, with 28 of its 30 components closing lower. Pfizer Inc. and UntiedHealth Group Inc. led the losses, down 3.1% and 4.4%, respectively. The one-day drop was the biggest since May 2017.

The S&P 500 SPX, -1.11% fell 31.10 points, or 1.1%, to 2,822.43, its biggest one-day decline since August, according to FactSet.

The Nasdaq Composite Index COMP, -1.07% declined 64.02 points, or 0.9%, to 7,402.48.

Market internals showed broad-based selling, but nothing that approached panic levels.

What are the drivers for the markets?

Losses on Wall Street were broad-based, but were primarily driven by health-care, energy, financials and technology shares, which were down between 1% and 2%.

But rising borrowing costs were also putting pressure on equity values. Rising bond yields can crimp demand for assets perceived as riskier, such as stocks, particularly when those yields are higher than those of equities.

On Monday, the yield on the benchmark 10-year Treasury TMUBMUSD10Y, 0.660% shot to 2.695%, its highest level since April 2014, having touched an intraday high of 2.727%. The yield remained above the 2.7% level on Tuesday.

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What are strategists saying?

“Concerns are starting to enter the market that inflation could be catching up and higher interest rates could pour cold water on the bull run,” said Jasper Lawler, head of research at London Capital Group, in a note. “Higher costs of borrowing could potentially put those companies under pressure, which have been relying on cheap money to grow.”

Some strategists played down Tuesday’s selloff.

“Despite the hiccup in the market, the bigger picture remains positive: The economy is finally growing faster than in the previous nine years, and businesses, especially job-creating small businesses, are doing well,” said Karyn Cavanaugh, senior market strategist at Voya Financial.

“The selloff in health-care stocks is overblown. Maybe the industry will have to be smaller because everyone else is trying to reign in health-care costs, but ultimately, that’s a plus for consumers,” Cavanaugh said.

What’s on the economic docket?

Home prices continue to surge well ahead of inflation and wage gains. The S&P/Case-Shiller 20-city index rose a seasonally adjusted 0.7% in November, and 6.2% for the year.

Consumer confidence rebounded in the first month of the new year, climbing to 125.4 in January from a revised 123.1 at the end of 2017.

Which stocks were key movers?

Shares of Dow component UnitedHealth Group UNH, +0.99% dropped 4.4% following the announcement by Amazon AMZN, -1.78% , Berkshire BRK.A, +0.36% and JPMorgan Chase JPM, -0.21% that they would partner in an effort to cut health-care costs and improve services for U.S. employees. Pharmacy-benefit managers, pharmacy chains and drug distributors were also hit. The SPDR Health Care Select Sector ETF XLV, -0.15% dropped 2%.

Health insurers were among the top decliners.Signa Corp CI, -0.63% dropped 7.2%, while Anthem Inc. ANTM, +0.45% dropped 5.3%. Aetna Inc. US:AET fell 3%.

Harley-Davidson Inc. HOG, -2.05% shares tumbled 8% after the motorcycle maker posted a sales drop. Pfizer Inc. PFE, -0.51% gave up early gains to close 3.1% lower even as the pharmaceutical group posted stronger-than-expected earnings.

McDonald’s Corp. MCD, -1.03% reported earnings that beat estimates but shares were still down 3%. Corning Inc. GLW, -1.15% shares fell 2.6% after earnings results.

Apple Inc. AAPL, -3.17% shares slipped 0.6%, after The Wall Street Journal reported that the company is cutting production for the iPhone X for the quarter ending March 31. A similar report in the Nikkei Asian Review weighed on shares Monday.

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MetLife Inc. MET, +0.89% shares sank 8.6% after the insurer said Monday that it will postpone earnings and revise prior financial reports over unpaid pensions.

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What are other markets doing?

Monday’s Wall Street selloff echoed around the globe, as European stocks lost ground and Asian equity markets came under pressure Tuesday.

The ICE U.S. Dollar Index DXY, +0.41% erased an earlier gain and fell 0.1% to 89.253, while gold futures US:GCG8 slid $3.50 to $1,336.80 an ounce.

Oil futures US:CLH8 lost nearly 2% to trade near $64.35 a barrel.

Bitcoin BTCUSD, -1.56% prices dropped 9.5% to around $10,101.