Rapid inventory declines increase pressure on the global oil market

Overview

This report is UBS's monthly institutional data snapshot of the global oil market, focusing on changes in IEA, EIA, OPEC and UBS's own forecasts. The report argues that recent oil prices have mainly been driven by a potential U.S.-Iran agreement and disruptions to Hormuz Strait flows; meanwhile, the latest institutional data confirm that supply disruptions are rapidly drawing down global inventories, making market tightness greater than previously expected.

Core views

UBS's core view is that the global oil market supply deficit has widened materially and that falling inventories are already supporting prices. UBS expects the 2Q26 supply-demand balance to be -6.7Mb/d, 3.4Mb/d tighter than its previous forecast; the average deficit for full-year 2026 is -1.4Mb/d, and although 4Q26 may turn to a 2.2Mb/d surplus, restocking demand should keep the market relatively tight into 2027. If Hormuz disruptions persist, Brent could move into the $120+/bbl demand-destruction zone; if tensions are quickly resolved and transit resumes, Brent could fall back to the mid-$80s, and with even faster supply recovery could return to the $60s/bbl.

Analysis framework

The report combines institutional forecast comparisons, supply-demand balance calculations, inventory simulations and scenario analysis. UBS cross-checks the monthly forecast revisions from IEA, EIA and OPEC against its own model, with a focus on Gulf supply losses, Iranian exports, Hormuz shipping flows, global inventories, refined product demand, non-OPEC+ output growth and the U.S. shale response.

Methodology notes

• Supply-demand balanceInstitutional forecast comparison

  Compare IEA, EIA, OPEC and UBS forecasts for demand, supply and inventory revisions.

  This method is used to judge whether this month's forecast changes are bullish or bearish for oil prices. The report says IEA and EIA revisions this month are clearly bullish, while OPEC's changes are modest.

• Scenario analysisBrent price scenarios

  Build price paths around the duration of Hormuz disruptions, U.S.-Iran talks and the pace of OPEC+ restoration.

  The base case assumes flows gradually recover starting in June; the upside case assumes Middle East disruptions persist into the summer; the downside case assumes a quick resolution of the conflict and faster OPEC+ output recovery.

• Inventory modelGlobal inventory restocking pressure assessment

  Estimate inventory lows and the restocking cycle using monthly inventory declines and supply-demand gaps.

  UBS expects global inventories to be about 7.6bn bbls by end-May; if restocking proceeds at roughly 2Mb/d, recovery of net lost inventories could take close to a year, while recovery of gross lost inventories could take about 18 months.

Asset mapping & comparison

Structured mapping from thesis to named assets (strengths, weaknesses, peers, risks).

• Brent crude

  Core price benchmark

  Strengths

  Falling inventories, the large 2Q26 supply deficit and Hormuz risk premium provide support.

  Weaknesses

  If the conflict eases and flows resume, Brent could fall back to the mid-$80s or even the $60s/bbl.

  Comparison

  Compared with last month, the IEA, EIA and UBS balance sheets are all tighter, with EIA's deficit forecast the most aggressive.

  Risks

  Progress in U.S.-Iran talks, faster OPEC+ production increases, global economic slowdown and demand destruction.

• U.S. shale oil and U.S. liquids output

  Source of supply response under high oil prices

  Strengths

  UBS raises 2026 U.S. supply growth to 0.4Mb/d, and EIA and IEA also raise U.S. growth forecasts.

  Weaknesses

  Rig activity is still weak in the near term, and recent export growth has come more from inventory drawdowns than from production increases.

  Comparison

  U.S. growth is weaker than Latin America's contribution, but it remains an important source of non-OPEC+ incremental supply.

  Risks

  Insufficient drilling and completion activity, cost pressure, price declines and SPR release disruptions.

• Latin American supply

  Main source of non-OPEC+ growth

  Strengths

  Latin America is expected to contribute 0.8Mb/d of incremental supply, supported by Brazil's Buzios 8 and other new projects as well as ramp-ups.

  Weaknesses

  Project start-up timing and regional operational risks could still limit growth.

  Comparison

  The report says Latin America leads U.S. contributions and is the main driver of non-OPEC+ supply expansion in 2026.

  Risks

  Project delays, infrastructure bottlenecks and oil price declines.

• Middle East and Gulf supply

  Primary source of the current market deficit

  Strengths

  If Hormuz reopens, underlying capacity has not been seriously damaged, so exports could recover quickly.

  Weaknesses

  Most spare capacity is currently in the Gulf and unavailable, Iranian exports have fallen sharply, and May supply losses are expected to exceed 15Mb/d.

  Comparison

  Gulf disruptions outweigh the improvement in non-Gulf non-OPEC+ supply.

  Risks

  Prolonged Hormuz disruptions, continued U.S. blockade and uncertainty over the pace of OPEC+ recovery.

Key data

• IEA inventory decline estimate247MbCombined inventory decline in March and April, equivalent to roughly >4Mb/d.
• UBS 2Q26 supply-demand deficit-6.7Mb/d3.4Mb/d tighter than the previous forecast.
• EIA 2Q26 supply-demand deficit forecast-8.5Mb/dEIA expects a -4.4Mb/d deficit in 3Q26.
• IEA 2Q26 supply-demand deficit forecast-6.0Mb/dIEA expects a -1.9Mb/d deficit in 3Q26.
• End-May global inventory estimateabout 7.6bn bblsUBS says this is the lowest level in the past five years.
• May Gulf supply loss>15Mb/dMainly due to prolonged Hormuz disruptions and lower Iranian output under the U.S. blockade.
• 2026 global oil demand growth-0.5Mb/dUBS lowered its full-year demand growth forecast by about 450kb/d.
• 2Q26 global oil demand-2.6Mb/d y/yOECD about -1.0Mb/d, non-OECD about -1.6Mb/d.
• 2026 non-OPEC+ supply growth0.1Mb/dUBS cuts the forecast by 400kb/d, but raises the non-Gulf region forecast by 330kb/d.
• 2026 U.S. supply growth0.4Mb/dUBS raises the forecast by 150kb/d; EIA and IEA also raise U.S. supply forecasts.

Impact & implications

The implications for oil prices and energy assets are bullish: supply disruptions and falling inventories are supporting near-term oil prices, and even after supply recovers, restocking demand could extend the period of tightness. Energy equities and upstream producers may benefit from high oil prices, while refining, petrochemical feedstocks, aviation fuel and non-OECD Asian demand are under pressure. If geopolitical tensions ease quickly, the downside risk to oil prices rises sharply.

Risks

• Hormuz traffic resumes faster than expected, causing oil prices to fall quickly.
• OPEC+ production recovery or output increases come faster than UBS's base case.
• A global economic slowdown triggers an additional demand downgrade of about 0.5Mb/d.
• A recovery in Venezuela, full normalization in Iran or higher supply from other regions could push Brent lower.
• Middle East disruptions lasting into the summer could push oil prices into a more severe demand-destruction zone.

What to watch

• Progress in U.S.-Iran talks and changes to the U.S. blockade.
• Daily vessel traffic through the Strait of Hormuz and Gulf export flows.
• Future monthly supply-demand balance revisions from IEA, EIA and OPEC.
• The monthly decline in global inventories and whether historical data are further revised downward.
• U.S. rig counts, DUCs, SPR releases and crude export data.
• The pace of actual OPEC+ production recovery and capacity arrangements after the UAE's exit from OPEC.