A drop of over $15 per barrel in Brent crude since May 18 could support the euro, pound and yen if Hormuz shipping resumes, Macquarie strategists said in a Friday note.
"Should crude oil prices continue to fall as a result of an opening of the Strait of Hormuz that comes with a ceasefire agreement, the beneficiaries (all else equal) will be the currencies of the energy
importing countries, such as the EUR, GBP, and JPY," according to the note.
Macquarie said energy-importing economies stand to benefit the most if a ceasefire leads to the reopening of the Strait of Hormuz and pushes oil prices closer to pre-conflict levels.
Markets increasingly view the reopening of Hormuz as a key condition of any extended US-Iran ceasefire, although negotiations still require approval from both US and Iranian leaders.
Even if an agreement emerges, shipping activity may take time to recover because operators could first need to remove mines from the waterway.
One proposal reportedly gives Iran 30 days to complete that process.
As traders priced in a lower risk of prolonged disruptions, crude prices retreated sharply over the past week, helping drive gains in global bond and equity markets.
The US Dollar Index has weakened only modestly since May 18, but Macquarie expects foreign-exchange markets to respond more strongly if oil prices continue falling.
Higher energy costs have already pressured major importing economies. Eurozone consumer inflation reached 3% in April from about 2% before the conflict, while preliminary data point to a reading near 3.3% in May.
With wage growth running near 2.5% on an annualized basis, rising prices have likely reduced real incomes across the euro area, even as expectations for a European Central Bank rate increase remain in place.
The United Kingdom faces similar challenges, with May composite Purchasing Managers' Index data remaining below 50 and real wage growth showing little improvement since the first quarter, according to the report.
In Japan, higher energy costs prompted the Bank of Japan to cut its 2026 growth forecast to 0.5% from 1.0% and raise its core inflation outlook to 2.8%, Macquarie said.
Japanese authorities have largely relied on foreign-exchange intervention instead of tighter monetary policy, spending about $74 million in May to support the yen against speculative pressure, the report said.
A Brookings Institution analysis suggests temporary supply buffers could largely disappear by July if Persian Gulf oil flows remain constrained. Under that scenario, nearly half of the roughly 15 million barrels per day that moved through Hormuz before March could be removed from the market.
Macquarie said renewed Hormuz flows would therefore provide meaningful relief for oil-importing economies, supporting currencies such as the euro, pound and yen.
Macquarie highlighted the Cleveland Federal Reserve trimmed mean inflation at 2.83% in May, up from 2.64% in March, with the monthly reading reaching 0.43%, or 5.2% annualized.
The firm cautioned that the outlook depends on lower oil prices. If crude remains elevated, the US dollar could stay firm as inflation pressures persist and the Federal Reserve leans toward keeping a tightening bias.