The U.S. stock market drifted higher in tentative trading ahead of a deadline President Donald Trump has set to bomb Iranian power plants.

The S&P 500 rose 0.4% Monday. The Dow Jones Industrial Average added 0.4%, and the Nasdaq composite climbed 0.5%.

Like stock indexes, oil prices seesawed through the day amid continued uncertainty about what will happen in the war with Iran and how long it will slow the global flow of crude oil. Trump warned again he will bomb Iran’s power plants if it doesn’t open the Strait of Hormuz.

Treasury yields held relatively steady in the bond market.

“We won’t merely accept a ceasefire,” Mojtaba Ferdousi Pour, head of the Iranian diplomatic mission in Cairo, told The Associated Press. “We only accept an end of the war with guarantees that we won’t be attacked again.”

Fighting is continuing, meanwhile, including an Israeli attack on an Iranian petrochemical plant. And in the background is the clock ticking toward a deadline, which Trump has moved multiple times, where he has threatened to attack Iran's infrastructure if it does not open the Strait of Hormuz. A fifth of the world’s oil typically sails through the strait during peacetime.

“Tuesday will be Power Plant Day, and Bridge Day, all wrapped up in one, in Iran,” Trump said on his social media network over the weekend, threatening Iranian leaders that “you’ll be living in Hell — JUST WATCH!”

Monday also offered the first chance for U.S. stock prices to react to a report from Friday that said U.S. employers hired more workers last month than economists expected. The unemployment rate unexpectedly improved.

They’re encouraging signals for an economy that’s had to absorb painful leaps in costs for gasoline since the war’s beginning.

The average price for a gallon of regular gasoline is nearly $4.12 across the country, according to AAA. It was below $3 a couple days before the United States and Israel launched attacks to begin the war in late February.

For countries that don’t produce as much oil as the United States, the pain has been even worse. That’s because they are more reliant on oil coming from the Middle East, and the war has blocked in much of the crude produced in the Persian Gulf area. That oil typically gets to customers around the world by exiting the Strait of Hormuz.

The price for a barrel of benchmark U.S. crude rose 0.8% to settle at $112.41 after erasing an earlier modest dip. Brent crude, the international standard, added 0.8% to $109.77 per barrel and remains well above its roughly $70 price from before the war.

On Wall Street, a split performance for the Big Tech stocks that are the U.S. market’s most influential kept things in check. Apple rose 1.3%, and Amazon added 1.2%. Tesla slid 2.6%, and Microsoft fell 0.3%.

Bank stocks were some of the market’s strongest, including a 1.5% rise for JPMorgan Chase.

CEO Jamie Dimon said in his annual letter to shareholders released on Monday that the U.S. economy continues to be resilient, and businesses still look healthy. He, though, also acknowledged that prices for stocks and other assets are high, which could imply “anything less than positive outcomes could have a dramatic impact on global markets.”

In the bond market, Treasury yields held relatively steady. The 10-year Treasury yield was sitting at 4.33%. That's still well above its 3.97% level from before the war. The rise has pushed up rates for mortgages and other loans going to U.S. households and businesses, which slows the economy.

A mixed report on Monday said that finance, transportation and other U.S. businesses in services sectors grew in March for a 21st straight month of expansion. But the growth was slightly slower than economists expected, and a measure of prices accelerated at its fastest pace since 2022 in a potentially discouraging signal for inflation.

In stock markets abroad, Japan’s Nikkei 225 added 0.5%, and South Korea’s Kospi jumped 1.4%. Many other markets in Europe and Asia were closed for holidays.