Oil futures rose on Sunday night after US strikes on Iran’s three main nuclear sites intensified fears of a potential supply shock, amid the threat that Tehran could retaliate by closing a key maritime chokepoint.

Brent crude (BZ=F), the international benchmark, gained as much as 5.7% before paring gains to trade near $79 per barrel. West Texas Intermediate (CL=F) futures also jumped more than 2% to trade north of $75 per barrel.

Oil prices had already posted weekly gains on Friday following the outbreak of conflict between Israel and Iran more than a week ago.

On Sunday, traders weighed possible retaliation moves from Iran, a major oil producer and exporter, following the US’s direct involvement.

According to state media, Iran’s parliament voted to close the Strait of Hormuz. The final decision on whether to shut the vital waterway — which handles roughly 20% of global oil flows — rests with Iran’s Supreme National Security Council and Supreme Leader Ayatollah Ali Khamenei.

What Wall Street once viewed as a low-probability event is now being treated as a significantly heightened risk.

“Should oil exports through the Strait of Hormuz be affected, we could easily see $100 oil,” said Andy Lipow, president of Lipow Oil Associates.

Following the outbreak of the Israel-Iran war, JPMorgan analysts forecast that under a “severe outcome,” a closure of the Strait of Hormuz could push oil prices to $120–$130 per barrel.

If crude climbs into that range, analysts predict gasoline and diesel prices could rise by as much as $1.25 per gallon.

“Consumers would be looking at a national average gasoline price of around $4.50 per gallon—closer to $6.00 if you’re in California,” Lipow said.