What is the actual oil flow through the Strait of Hormuz? US Department of Energy data differs from market tracking data by a factor of two

A data dispute is erupting between the US Secretary of Energy and Wall Street analysts over oil flow through the Strait of Hormuz, with their estimates differing by almost a factor of two, causing global oil markets to be plunged into an information muddle. Analysts believe this dispute is not just about numbers; it directly influences market expectations regarding the global supply gap and whether oil prices can remain stable at current levels.

According to CNN on August 17, US Secretary of Energy Chris Wright publicly stated last week that the seven-day average daily oil flow through the Strait of Hormuz has risen to 9 million barrels, and that on August 8th alone, the total volume of oil exiting the Arabian Gulf exceeded 20 million barrels, matching pre-war levels. He emphasized that the US military is providing escort operations in the strait, allowing the Department of Energy to access "the highest quality available data." However, data from third-party ship tracking firms such as Kpler and Windward Intelligence shows current daily tanker transport through the strait is about 4 million barrels, plus an estimated 7 million barrels via pipelines and other bypasses, totaling around 11 to 12 million barrels, far lower than the Department of Energy data.

This data gap has a considerable impact on the market. Global crude inventories have fallen by 1.5 to 1.9 billion barrels since the war began, and the oil market has consistently been in a supply-deficit state. If the DOE data is accurate, concerns about supply shortfalls may have been overstated; but if tracking data is more precise, the "tipping point" for exhausting global inventory could arrive much sooner than the market expects.

The Data Gap: 9 Million vs. 4 Million Barrels

The core of the dispute lies in the massive divergence between the two data systems.

The 9 million barrels daily flow cited by Wright comes from real-time monitoring of vessels in the strait conducted by the US military. A DoE spokesperson stated, "Working with the US military, the Department of Energy maintains the highest-quality available data related to the outflow of oil and oil products from the Arabian Gulf."

In contrast, Wall Street analysts have long relied on Kpler data, which paints a very different picture. Kpler has 13,000 proprietary receivers in 190 countries, tracks 350,000 ships, updates vessel locations every five minutes, and also operates a low-earth-orbit satellite network. The company’s head of commodities research Matt Smith said bluntly:

"The gap between the data we observe and the numbers he cites simply cannot be reconciled."

On August 8, the day Wright claimed single-day outflows topped 20 million barrels, Kpler and Windward Intelligence each recorded only about five ships passing through the Strait of Hormuz. Prior to the war, more than 100 ships crossed daily. "With only this few vessels, there’s no way they could carry such volumes of oil," analysts pointed out.

Hamad Hussain, Senior Climate and Commodities Economist at Capital Economics, commented:

"It is becoming increasingly difficult to determine how much oil is actually leaving the Gulf. Contradictory statements from US and Iranian officials are muddying the waters."

Shadow Fleet: The Data Blind Spot May Be Larger Than Imagined

Even as tracking firms stand by their data, analysts concede that significant blind spots may exist in the current market information landscape.

In recent weeks, Iranian attacks on transiting ships have visibly escalated, with its Houthi allies also growing more aggressive in the Red Sea. This has forced an increasing number of tankers traversing the Strait of Hormuz and Bab el-Mandeb to do their utmost to hide their positions and cargo details, to avoid attacks.

Kpler data shows that in recent weeks, about half of the flows passing through the Strait of Hormuz have been "shadow movements"—that is, covert sailings with transponders switched off, compared to only about one-eighth of transit a month ago.

Windward Intelligence also uses satellite imagery and AI to track ships with disabled transponders, but the DOE believes that even so, a significant number of ships still go untracked.

Hussain points out that when these slow-moving tankers leave dangerous waters and switch their transponders back on, the market may realize that far more oil has actually left the region than previously estimated. This means the current judgment of supply shortages could be overstated.

Wall Street: From Skepticism to "Trust but Verify"

Within this data debate, Wall Street’s stance is subtly shifting.

Previously, analysts were generally skeptical of the Trump administration’s assertions. Trump repeatedly claimed that America controlled the Strait of Hormuz and often hinted that a deal with Iran was imminent; Wright likewise emphasized that the US was ensuring ample oil supply. The market viewed such statements as a form of "verbal intervention" to keep prices low and did not include them in mainstream analysis frameworks.

However, this attitude is loosening. This past June, Natasha Kaneva, Global Head of Commodities Strategy at JP Morgan, said relatively tepid oil prices prompted her to re-examine actual crude outflows from the Persian Gulf and acknowledged a significant volume of "secret" oil might be leaving undetected, via tankers with switched-off transponders. JP Morgan includes Kpler’s shipping data among several sources in its supply and demand estimates.

Dan Pickering, founder and CIO of Pickering Energy Partners, said he keeps an open mind regarding the DOE figures. "The US is helping move a considerable volume of oil through the strait, and Iran isn’t stopping all vessels," he said. "In an environment where the government has accumulated plenty of skepticism, ‘trust but verify’ may be the best stance you can take. Of course, what he says could be right."

Inventory Critical Point: The Real Market Risk

No matter how the data dispute eventually ends, analysts note that the direct influence of accurate Hormuz flow figures on oil prices is less important than their long-term significance for market stability.

Since the war began, global crude inventories are down by 1.5 to 1.9 billion barrels (depending on the estimation system). The vast prewar inventories have, to some degree, cushioned the blow from supply plunges and helped avert a wider market crisis.

Currently, the oil market remains in a continuous supply deficit. The more oil that flows through the strait, the longer the market can postpone the exhaustion "critical point"—the moment when reserves are insufficient to meet global demand.

"The market cannot rely on working off inventory forever," Pickering warned. "Eventually, reserves will hit bottom."

This means that, if the tracking agencies' data is closer to reality, current oil prices may be underpricing the actual supply risks the market faces, and downside risks are more severe than prices currently reflect.