By Anna Isaac and Paul Vigna 

Stocks slipped Tuesday as U.S. companies began reporting earnings and China's exports grew at the slowest pace in three years, adding to concerns about a wider global slowdown.

The S&P 500 dropped 0.1%, and the Nasdaq Composite lost 0.2%. The Dow Jones Industrial Average swung between small gains and losses. Elsewhere, the Shanghai Composite Index closed for the day down 0.3%, while the pan-continental Stoxx Europe 600 index edged up 0.2%.

A rally in financial stocks helped offset losses in most other sectors, after JPMorgan and Citigroup reported strong fourth-quarter results to kick off the corporate earnings season.

The equity market's gains though have come as corporate earnings growth in the U.S. has slowed sharply, said Ben May, the director of global macro research at Oxford Economics, resulting in stretched valuations. So while the fourth-quarter numbers are important, more critical will be what executives say about the rest of 2020.

"It perhaps creates more downside risks if the economy underperforms or earnings don't improve to the extent expected," he said.

Banks got off to a mostly strong start to earnings season, though. Dow component JPMorgan and rival Citigroup reported strength in their investment banks in the last three months of 2019. Both stocks rose about 2.2%. Those gains helped push the Nasdaq KBW Bank index up 0.5%.

But Wells Fargo fell 3.9% after reporting its profit sank due to legal costs incurred from problems in its sales practices.

Delta Air Lines rose 3.4% after the airline said lower fuel prices and strong demand over the holidays helped boost its profit, which exceeded analysts' expectations. Meanwhile, Boston Scientific fell 8.1% after the medical-devices maker warned its sales would fall shy of expectations.

Also, Visa rose 0.3% after it agreed to buy fintech firm Plaid for $5.3 billion.

Overseas, exports from China climbed by 0.5% last year, a sharp comedown from 2018's expansion of nearly 10%, according to data released Tuesday. Imports dropped 2.8% last year.

While the slowdown comes amid a two-year trade war between the world's largest economies, China's foreign trade revived in December as tensions ebbed following signals that Washington was nearing a trade deal with Beijing. Investors in recent days have been cautiously optimistic about that accord as they await more information on the specific terms of the agreement.

China has committed to buying almost $80 billion of additional manufactured goods from the U.S. over the next two years, Reuters reported on Tuesday. The Asian giant would also purchase more than $50 billion more in energy supplies, and boost spending on U.S. services by roughly $35 billion, the news agency said, citing a person with knowledge of the matter.

"The overall mood music is positive, but the key thing is what the actual wording of the agreement is," said Edward Park, deputy chief investment officer in London for Brooks Macdonald Asset Management. "Investors need to see real progress on U.S.-China."

Separately, China's currency strengthened to its strongest level since July in offshore trading after the U.S. on Monday dropped it from a list of currency manipulators, days before the likely signing of a phase-one trade deal. The yuan pared back its gains later in the day.

Write to Anna Isaac at anna.isaac@wsj.com and Paul Vigna at paul.vigna@wsj.com

(END) Dow Jones Newswires

January 14, 2020 11:36 ET (16:36 GMT)