BusinessOil prices briefly fell under $100 US on Wednesday on hopes that Iran and the U.S. could make a peace deal, before rising again just over that mark. International markets soared and Wall Street posted more gains, with the S&P 500 and Nasdaq both reaching new highs.Brent crude fell below $100 US early Wednesday, before coming back to just above that markThe Associated Press · Posted: May 06, 2026 9:22 AM EDT | Last Updated: May 6Listen to this articleEstimated 4 minutesThe audio version of this article is generated by AI-based technology. Mispronunciations can occur. We are working with our partners to continually review and improve the results.A dealer walks past near the screen showing the Korea Composite Stock Price Index at a dealing room of Hana Bank in Seoul, South Korea, on Wednesday. (Lee Jin-man/Associated Press)Oil prices sank Wednesday and stock markets rallied worldwide with hopes that the United States and Iran are nearing a deal to allow ships to deliver crude from the Persian Gulf once again to their customers.The price for a barrel of Brent crude oil, the international standard, fell 7.8 per cent to just over $100 US a barrel, down from more than $115 US early this week. It dropped as U.S. President Donald Trump said on social media that the Strait of Hormuz could be "OPEN TO ALL" if Iran accepts a reported agreement that Trump did not detail.The small strait has caused big trouble for the global economy because the war with Iran has blocked oil tankers from using it to exit the Persian Gulf. A reopening could allow oil to flow freely again and remove upward pressure on inflation that's driven prices up for all kinds of products worldwide.On Wall Street, the S&P 500 climbed 1.5 per cent for its best day in nearly a month and hit another all-time high. The Dow Jones Industrial Average jumped 612 points, or 1.2 per cent, and the Nasdaq composite rose two per cent to its own record.At close, Canada's S&P/TSX composite index was up about 1.2 per cent at 33,981.82.Stock markets abroad had even bigger gains. Indexes jumped 6.5 per cent in Seoul, 2.9 per cent in Paris and 2.1 per cent in London.Hopes have risen several times already on Wall Street about a possible end to the war with Iran, only to quickly get dashed. That could happen again, and oil prices pared some of their steepest losses from Wednesday morning. The price for a barrel of Brent briefly dove to around $97 US before returning above $100 US after Trump threatened to start bombing "at a much higher level and intensity" if Iran does not accept the agreement.But Wall Street nevertheless latched onto potentially encouraging signals. Trump said Tuesday he was pausing his effort to forcefully reopen the Strait of Hormuz to commercial ships.And China's foreign minister called for a comprehensive ceasefire following a meeting with Iran's foreign minister. That could be influential because of how closely tied Iran is to China economically and politically.Tehran evaluating U.S. proposal to end war, but Iranian lawmaker calls it 'American wish list'Trump pauses U.S. effort to guide vessels through Strait of Hormuz in bid to make deal with IranIn the background, big U.S. companies continue to turn in much stronger profits for the start of 2026 than analysts expected. That's helping to support the stock market despite all the uncertainties about the war.WATCH | Why the blockade hasn't tanked markets — yet:Why the Strait of Hormuz blockade hasn't tanked markets — yetApril 13|Duration 1:53With the Strait of Hormuz now doubly blockaded, oil prices fell while markets climbed on Monday, despite an initial shock. CBC senior business correspondent Peter Armstrong explains where the pain is being felt, and how public faith in a solution could be buoying the markets.Chip company AMD helped lead the market with a surge of 18.6 per cent after it joined the list of big-name firms topping expectations for both profit and revenue. CEO Lisa Su said the company benefited from continued growth from artificial intelligence technology, which is demanding tremendous amounts of computing power from data centers.Another company enmeshed in the AI industry, Super Micro Computer, rallied 24.5 per cent after likewise delivering stronger earnings than analysts expected. Nvidia, the chip company that became the poster child of the AI boom, rose 5.7 per cent and was the single strongest force lifting the S&P 500 because of its immense size.Outside of earnings reports, companies with big fuel bills jumped on hopes that oil prices will continue to ease. That included gains of 6.8 per cent for United Airlines, 6.8 per cent for Carnival and 8.8 per cent for Royal Caribbean.In the bond market, Treasury yields sank as falling oil prices took pressure off inflation. The yield on the 10-year U.S. Treasury dropped to 4.35 per cent from 4.43 per cent late Tuesday. That's a notable move for the bond market.With files from CBC News