Oil prices crashed as much as five percent and stocks soared across Asia on Monday after the United States and Iran announced a peace deal that'll reopen the Strait of Hormuz. It ends three months of conflict that had sent energy prices through the roof.

Mediator Pakistan confirmed the agreement, with a signing ceremony set for June 19 in Switzerland. US President Donald Trump, marking his 80th birthday on Sunday, wrote on social media: "The Deal with the Islamic Republic of Iran is now complete. I hereby fully authorize the toll-free opening of the Strait of Hormuz, and, simultaneously herewith, authorize the immediate removal of the United States Naval blockade. Ships of the World, start your engines. Let the oil flow!"

Iran's Deputy Foreign Minister Kazem Gharibabadi confirmed on television that the deal puts an "immediate end" to the war, with talks on a "final agreement" to follow within two months. The exact terms of the agreement remain unclear.

The Strait of Hormuz is a vital maritime chokepoint through which roughly 20 percent of the world's crude oil supply passes. Tehran effectively closed it soon after US-Israel strikes on Iran kicked off the conflict on February 28, sending oil prices surging past $110 a barrel.

By Monday morning, West Texas Intermediate crude had fallen 5.6 percent to $80.16 a barrel — its lowest since early March. Brent North Sea crude dropped 4.1 percent to $83.77. The sharp drop in oil costs soothed growing fears that soaring inflation could force central banks to start hiking interest rates again.

Just last week, data showed a jump in US May consumer prices and strong job creation, ramping up bets that the Federal Reserve would tighten before year-end. "Oil down takes the inflation impulse down. Lower inflation risk takes some of the Fed-hike premium out of the curve," said Stephen Innes at SPI Asset Management. "The dollar loses a bit of its wartime bid. Crypto, always the fastest animal in the speculative zoo, gets launched by the same liquidity impulse. In one headline chain, the market moves from bunker pricing to reopening pricing."

But Innes cautioned: "This is a first step deal, not a final peace settlement. The market will now trade verification" — including the signing in Switzerland, mine clearance in the Strait, and restraint by Israel and Hezbollah.

Asian equities surged. Tokyo's Nikkei 225 jumped 5.4 percent to 69,593.64, led by tech investor SoftBank and chipmakers Tokyo Electron and Advantest. Seoul's KOSPI piled on more than five percent, with Samsung and SK hynix leading. The rally was also fuelled by last week's record-breaking $75 billion IPO from Elon Musk's SpaceX, which rallied 19 percent on debut and made Musk the world's first trillionaire, reigniting the AI trade.

Shanghai, Sydney, Singapore, and Taipei all rose more than one percent. Jakarta jumped more than four percent as easing energy costs supported the beleaguered rupiah, which strengthened to 17,700 per dollar — its best level since late May, after touching a record low of 18,209 earlier this month.

For Nigeria, a major oil exporter, the price crash is a double-edged sword. Lower crude prices mean reduced government revenue and pressure on the naira, but also lower fuel import costs and potential relief for consumers if the government passes on savings. The Nigerian economy, already grappling with high inflation and a weak currency, will be watching closely as the deal unfolds.