Energy, financials were top-performing sectors in key index

Standard & Poor’s 500 bounced back from flat results in 2015.

NEW YORK — In 2016, the Standard & Poor’s 500 index jumped 9.5 percent and bounced back from a flat result the year before, and energy companies and banks made some of the largest gains as investors bet on a stronger economy that will lead to more lending and spending. Health care companies slumped as drug prices came under intense scrutiny.

Energy: up 23.7 percent

At the beginning of the year it looked like 2016 would be another painful one for energy companies. In February oil traded at $26 a barrel, down from more than $100 in mid-2014. But over the next few months oil prices rose gradually rose above $50, which reduced the scope of their losses. Late in the year, OPEC and other oil producers agreed to cut their production in 2017. The price of U.S. crude finished the year up 45 percent. Oil and gas company Oneok more than doubled in value for the year while Chevron had its best year since 1989.

Financials: up 20.1 percent

Banks and other financial companies sank early in 2016 as investors worried about slowing global economic growth. After that they struggled as the Federal Reserve continually held off on raising interest rates. But the sector caught fire leading up to the election and afterward, as investors felt banks will be major beneficiaries of a Donald Trump administration. Banks stand to benefit from increased government spending and borrowing connected to greater spending on infrastructure, as well as faster economic growth, looser regulations and rising interest rates.

Industrials: up 17.8 percent

Companies that make construction equipment, engines and aircraft also made large gains as the U.S. economy picked up steam. Investors bet that the election of Trump, and a Republican Congress that could approve his spending proposals, will lead to more spending on construction, manufacturing, and transportation. The sector, which includes companies like Boeing and General Electric, reached all-time highs at the end of the year. Caterpillar was the best-performing Dow Jones industrial average component in 2016 while farm equipment maker Deere rose to an alltime high.

Technology: up 12 percent

Technology companies rose for the eighth year in a row. The stocks surged this summer as the U.S. economy appeared to gain strength, while critical overseas markets also looked healthier. The technology sector didn’t do as well following the election, however, as investors wondered if Trump’s trade and immigration policies and his inflammatory rhetoric would hurt their sales overseas. Graphics processor company Nvidia more than tripled in value and performed better than any other S&P 500 stock, while Hewlett-Packard’s breakup left two stocks that both did well.

Health care: down 4.4 percent

Drug makers were pummeled in 2016 as their pricing strategies came under repeated criticism and congressional scrutiny. Biotechnology companies like Vertex and Alexion were hit especially hard. Endo slumped thanks to legal costs and weak earnings. Some insurance companies, including UnitedHealth and Aetna, traded higher. One reason is that Wall Street thinks the possible repeal of the Affordable Care Act will strengthen their profits. Overall, health care stocks fell for the first time since 2008.