Oil Market on a Knife's Edge: Macquarie Warns of Oversupply If U.S.-Iran Diplomatic Deal Sticks

Oil prices have swung wildly over the past six months as the U.S.-Iran conflict disrupted global supply, but the trajectory could reverse sharply if diplomatic efforts succeed. Macquarie Group issued a stark warning on July 27, 2026: oil markets could tilt back into oversupply by year-end if the current U.S.-Iran pause leads to a lasting deal . Here's what that means for prices, supply, and the risks ahead.

Macquarie's Core Warning: Oversupply Before Year-End

In a note published July 27, Macquarie warned that oil markets could tilt back into oversupply before the end of the year if the current U.S.-Iran pause leads to a lasting diplomatic deal . Macquarie's energy strategist, Vikas Dwivedi, said de-escalation is "weeks away, not months" . Dwivedi framed the dynamic in options-market terms: "They're long a put option, but that value is decaying with time and the expiration date is the midterms" .

The Political Driver: Gasoline Prices and the Midterm Clock

Macquarie explicitly links the urgency to the U.S. political calendar. Washington faces mounting pressure to end the Iran conflict with fewer than 100 days until the midterm elections . The desire to bring down gasoline prices ahead of the vote is a major driver for the administration to secure a deal quickly .

Forecast	Macquarie (June 24)	Morgan Stanley (June 30)
Brent 2026 avg	$77/bbl	—
Brent 2027 avg	$64/bbl	$70–75/bbl H1-H2 2027
Brent 2026 Q3	—	$75/bbl
Brent 2026 Q4	—	$80/bbl

Price and Supply Forecasts Compared

Macquarie's Revised Numbers

On June 23–24, 2026, Macquarie slashed its Brent forecasts, seeing a rapid return of Hormuz flows after the interim peace deal . By June 24, Macquarie forecast Brent at $77/barrel for 2026 and $64/barrel for 2027, down sharply from earlier projections of $89 and $74 . This contrasts with Macquarie's March 2026 worst-case scenario, where it warned oil could hit $200/barrel if the war and Hormuz closure extended to June .

Morgan Stanley's Sequential Cuts

Morgan Stanley's forecasts tell a similar story of rapid downgrades:

• April 13: Maintained Q2 2026 Brent at $110 and Q3 at $100, expecting slow supply recovery .
• Mid-June (after MOU): Revised Q3 to $90 and Q4 to $80, noting physical recovery would take weeks but price signals were already declining .
• June 30: Lowered Q3 2026 to $75 and Q4 to $80, flagging a larger surplus expected in 2027, with Brent at $75 in H1 2027 and $70 in H2 2027 .
• The bank cited strong U.S. supply and weak Chinese demand as additional surplus risks .

The Actual Price Collapse

The market has already priced in much of the de-escalation:

• Brent crude fell from war-driven highs above $100+ to around $73–$77/barrel by late June 2026 .
• On July 27, oil prices tumbled 4% after the U.S. and Iran paused strikes .
• The IEA's July 2026 report said North Sea Dated prices plunged by $31/barrel in June alone to $68/barrel by early July—their lowest level since before the war .

Timeline of De-Escalation: Fragile Steps Forward

The Original MOU (June 17)

A 60-day ceasefire Memorandum of Understanding was signed on June 17, 2026, with a 60-day negotiation window for a permanent deal . The Strait of Hormuz was to return to full capacity within 30 days under that agreement . However, the ceasefire was "always shaky" and frequently interrupted by flareups . By early July, hostilities escalated again, effectively shredding the ceasefire .

The New Pause (July 25–26)

A new pause occurred over the weekend of July 25–26, 2026, when the U.S. and Iran paused strikes after two weeks of renewed attacks, raising hopes of a renewed diplomatic solution . Macquarie sees a final deal as imminent—"weeks, not months" . Negotiations remain ongoing; the 60-day framework from the original MOU technically continues .

The Risk the Ceasefire Could Collapse

The ceasefire is fragile. On June 17, 2026, Trump simultaneously warned of a potential bombing campaign if Iran did not comply with the deal , underscoring the high tension. Iran has previously denied engagement with the U.S. during earlier phases , and the deal is contingent on continued nuclear negotiations in Switzerland . Any breakdown in those talks could collapse the ceasefire and re-escalate the conflict, reversing the supply surplus outlook .