The selloff comes after President Donald Trump warned more casualties are likely from Operation Epic Fury, joining the first ones reported, while the FBI is investigating a mass shooting last night in Texas as potential terrorism.

Earlier, Trump has suggested the conflict with Iran could last a while as he makes regime change a goal, saying on social media Saturday that the bombing will continue “as long as necessary to achieve our objective of PEACE THROUGHOUT THE MIDDLE EAST AND, INDEED, THE WORLD!”

But he also told The New York Times on Sunday evening that he’s open to lifting sanctions on Iran if the new leadership that replaces Supreme Leader Ali Khamenei, who was killed in an airstrike, can serve as a pragmatic partner.

Futures tied to the Dow Jones industrial average fell 353 points, or 0.72%. S&P 500 futures were down 0.68%, and Nasdaq futures lost 0.79%.

U.S. oil futures shot up 5.6% to at $70.77 a barrel, and Brent crude gained 5.9% to $77.15, after earlier spiking more than 8%. In over-the-counter trading earlier on Sunday, Brent prices jumped 10% to about $80 a barrel, oil traders told Reuters.

Iran pumped 4.7 million barrels per day last year, accounting for 4.4% of global oil supplies. But the bigger risk centers on the potential for Iran to close off the Strait of Hormuz, where a fifth of all the world’s oil passes through on the way to export markets. Analysts have estimated that any Iranian moves to close off the strait could send prices to $100 per barrel.

The Islamic Revolutionary Guards Corps has reportedly warned ships that passage is not allowed in the strait, and said Sunday that it struck three oil tankers with missiles. But even before that, fear of such attacks froze ship traffic.

Hundreds of tankers carrying oil and liquid natural gas had already dropped anchor or were stationary near the Strait of Hormuz, according to shipping data compiled by Reuters. That’s after tanker owners, oil majors and trading houses suspended shipments via the strait on Saturday as a precautionary move.

In addition, Greece’s shipping ministry has advised vessels to avoid the Persian Gulf, the Gulf of Oman and the Strait of Hormuz. And shipping giant Maersk said it is suspending all vessel crossings through the strait until further notice.

Closure of the strait would hit Asia the hardest, since most economies in the region are major oil importers whose supply routes depend on those lanes being open, according to Idanna Appio, a portfolio manager and senior analyst covering sovereign debt and foreign exchanges.

Alan Gelder, senior VP of refining, chemicals and oil markets at Wood Mackenzie, estimated it could take a few weeks for export flows to resume, even in the most optimistic scenario where Tehran cooperates with the U.S. 

But until then, the outlook on prices has a heavy upside risk, he added in a note, drawing a comparison with the immediate aftermath of Russia’s invasion of Ukraine in 2022, when oil hit $125 a barrel.

To be sure, additional supply could lessen the blow. OPEC+ agreed to boost oil production, with plans to increase output by 206,000 barrels a day in April from its 137,000-barrel monthly increments.

“There is, however, a risk that the OPEC+ decision is moot if flows do not resume through the Strait of Hormuz,” Gelder said.

Gold rose 2.3% to $5,367 per ounce, and silver climbed 1% to $94.25. The yield on the 10-year Treasury ticked up less than 1 basis point to 3.97%. The U.S. dollar was up 0.27% against the euro and was up 0.31% against the yen.

Early indications from Asian currency markets, where the Aussie dollar is viewed as something of a canary and was off about 0.28%, suggested that investors were moving defensively but not yet pricing in severe disruption, said Appio, who manages First Eagle’s Global Income Builder fund.

“I don’t think this feels like a liquidity type event,” she told Fortune.

As for sovereign risk in the Gulf, Iran has targeted Bahrain, Qatar, and the UAE with missiles and drones. The situation weighs on regional risk on the margins, but most of those sovereigns carry strong balance sheets, Appio explained.

If anything, it might signal a buying opportunity for investors rather than structural deterioration. The longer-term question is whether this current conflict resolves in a way that reduces regional risk, but she said that’s a scenario for the future and not necessarily the week ahead.

Investors will also look ahead to a busy week for economic indicators. On Monday, the Institute for Supply Management will release its monthly manufacturing activity index. On Wednesday, ADP will publish its monthly data in private-sector payrolls, and the Federal Reserve will put out its beige book report on regional business and economic conditions. On Thursday, fourth-quarter productivity data comes out. And on Friday, the Labor Department will issue its monthly jobs report.