Oil flows through the Strait of Hormuz are recovering, yet the visible market data only captures a fraction of the real picture.

On Wednesday, a team of strategists led by Yulia Zhestkova Grigsby at Goldman Sachs informed clients that Gulf oil exports have bounced back to 15-16 million barrels per day, roughly two-thirds of pre-conflict levels.

However, visible shipping data only reflects approximately 10 million barrels per day of traffic. The five million barrel gap between those figures represents what the team describes as a "surge in dark transits" — tankers switching off their Automatic Identification Systems (AIS) to evade Iranian tracking and interception. Brent crude has climbed to $95 per barrel, signaling that markets are now pricing in a "no-deal" Middle East standoff as the longer-term baseline scenario.

Meanwhile, multiple officials from the Trump administration have voiced optimistic statements this week about the recovery of Strait oil flows, but the data from Goldman Sachs reveals a situation far more intricate than the official narrative suggests.

Officials Declare "Hormuz Is Back," Data Gap Raises Questions

Senior Trump administration figures delivered a flurry of statements this week regarding oil traffic through the Strait of Hormuz.

US Energy Secretary Chris Wright told CNBC on Monday that over 17 million barrels per day had passed through this critical waterway, marking the highest level in the six-month conflict. President Trump then announced on Truth Social, "The oil volume in Hormuz is back!" Vice President Vance also chimed in, noting that "15 million barrels came out of the Strait last night, thanks to US actions."

Yet, visible shipping data, calculated on a seven-day moving average, indicates traffic of only about 10 million barrels per day — a significant discrepancy when compared with the official figures.

The Goldman Sachs team noted in their report that this gap has widened substantially over the past two weeks, primarily driven by a large number of tankers disabling their AIS systems while transiting the Strait near the Omani coast. After incorporating the dark vessel data, Goldman Sachs estimates the net impact on Persian Gulf oil flows this week at approximately 7.9 million barrels per day. While this still constitutes a major supply disruption, it is significantly smaller than what appeared based solely on visible shipping data alone.

Additionally, Goldman Sachs pointed out that due to threats from the Houthi militants, Saudi Arabia has begun rerouting oil flows from the Yanbu terminal back toward eastern ports. Red Sea exports, which move via the Bab el-Mandeb Strait, Suez Canal, and SUMED pipeline, dropped by 4.5 million barrels per day in August compared with July, creating a partial offset.

Surge in Dark Vessels Triggers Revisions to Inventory Estimates

The expansion of dark vessel traffic has also had ripple effects on global crude inventory data. Goldman Sachs believes that current inventory readings may be understated, as high-frequency visible data underestimates the actual volume of crude in transit.

After applying upward revisions, Goldman Sachs estimates that global visible inventories are approximately 39 million barrels higher than the raw readings suggest, with inventory drawdown accelerating to about 2.1 million barrels per day over the past 30 days. This implies that the actual supply-demand balance in the oil market may be looser than surface data indicates.

The Grigsby team wrote that the disruption at the strategic Strait of Hormuz chokepoint is forcing Gulf producers and shipping operators to adapt faster than Wall Street tracking models can respond — oil is still moving, but an ever-increasing portion is "hidden in the dark."