Commodities & indices · Intermediate

Oil Markets And Supply-Demand Drivers

Oil is a supply story most weeks, and the weekly inventory report is the scheduled event most likely to decide your position.

Last reviewed 15 September 2026 by the MarketPro research desk · Editorial policy

In short

Crude oil prices are set by the balance between producer supply and refinery demand, with inventories as the visible scoreboard. Supply changes faster than demand, so most short-term volatility is a supply story: producer policy, shale output, disruptions and spare capacity. Weekly US inventory data every Wednesday is the single most reliable scheduled source of intraday volatility in oil.

What to remember

A 6.5 million barrel inventory surprise routinely moves WTI 1.50 USD, which is 1,500 USD on one 1,000 barrel contract in about twenty minutes.
Spare capacity decides whether a disruption is an inconvenience or a price shock, and almost nobody quotes it.
Geopolitical spikes decay when no barrels are actually lost. Separate a change in physical supply from a change in perceived risk.
Oil's daily range is often 2% to 3% of price and it gaps on the Sunday open. Derive the stop from ATR, not from a chart level alone.

Lesson 4 of 16 in Commodities and indices

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Crude oil prices are set by the balance between what producers put on the market and what refiners and consumers take off it, with inventories acting as the visible scoreboard. Supply is controlled by a small number of large producers and moves in policy-sized steps. Demand is enormous, slow and mostly predictable. Because supply can change faster than demand, most short-term volatility in oil is a supply story.

Wednesday at 15:30 London, in barrels and in dollars

The US Energy Information Administration publishes weekly petroleum inventories every Wednesday. Consensus might be for a 2.0 million barrel build. The print comes in at a 4.5 million barrel draw, a 6.5 million barrel surprise in the tighter direction.

A move of 1.50 USD on WTI in the following twenty minutes is entirely ordinary on a surprise of that size. On one futures contract of 1,000 barrels that is 1,500 USD. On a 0.10 lot CFD sized at 100 barrels it is 150 USD. If you are carrying 0.50 lots because the chart looked good and you had not checked the calendar, an adverse print costs 750 USD in under half an hour, and the spread widens while it happens so the exit is worse than the screen suggested a minute earlier.

The release time is published years in advance. Being surprised by it is a planning failure, not bad luck. Note also that the industry body publishes its own estimate the previous evening, which frequently moves price ahead of the official number and occasionally disagrees with it.

Supply: the handful of actors who can change the number

Coordinated producer policy. The large exporting group meets on a schedule and can add or remove barrels in increments of hundreds of thousands per day. The announcement matters less than the compliance rate that follows it.
US shale. The fastest-responding supply in the world, with a lead time measured in months rather than years. Rig counts and completion data give an early read.
Disruption risk. Sanctions, conflict, pipeline outages, hurricanes in the Gulf of Mexico. These arrive without a calendar entry and are the reason overnight gaps in oil are larger than the daily range suggests.
Spare capacity. The single most important number nobody quotes. When the world holds several million barrels a day of idle capacity, a disruption is an inconvenience. When it holds almost none, the same disruption is a price shock.

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Demand: bigger, slower, and mostly already priced

Global consumption is dominated by transport and industry, so it tracks economic growth with a lag and changes by low single-digit percentages a year. That makes it a poor source of trading signals in the short run, because forecasts are revised in small increments and the market has already read the same forecasts you have.

The exceptions are worth knowing. Chinese industrial data and refinery run rates move the market because the country is the largest importer. Northern hemisphere driving season lifts gasoline demand from roughly May to September. And a sharp deterioration in growth expectations can reprice demand quickly, which is why oil often sells off hard on a bad manufacturing survey while the supply picture is unchanged.

The headline spike that retraces by Friday

Oil responds violently to geopolitical headlines and then, in most cases, gives most of it back. The reason is that price initially reprices the probability of lost barrels, and if no barrels are actually lost the risk premium decays. Several conflicts in producing regions have produced double-digit percentage spikes that were fully retraced within a fortnight because exports never stopped.

The practical rule that follows is to separate two questions. Has physical supply actually changed, measurable in export loadings and inventories? Or has the perceived risk to future supply changed? The first tends to persist and the second tends to decay. Chasing the second one late is how a good read on the news becomes a losing trade.

Two benchmarks that are not the same trade

WTI and Brent are quoted within a couple of dollars of each other and are frequently treated as interchangeable. They are not. WTI is delivered inland at Cushing, Oklahoma, so it reflects US logistics and export capacity. Brent references waterborne North Sea grades and is the benchmark against which most internationally traded crude is priced.

The practical difference shows up when something goes wrong in one place and not the other. A pipeline constraint or a refinery outage in the US Midwest can push WTI several dollars below Brent while the global market is unchanged, and a disruption to seaborne exports elsewhere can do the reverse. If your analysis is about global supply risk, Brent is usually the cleaner expression of it. If it is about US inventories, WTI is. Trading one on a thesis built from the other is a mismatch that shows up as a position that is right about the news and wrong about the price.

What to have on the screen before an oil position

Keep a short weekly list: the industry inventory estimate on Tuesday evening, the official EIA report on Wednesday, the rig count on Friday, and any scheduled producer meeting. Add the current front-month against the six-month contract, because a curve in backwardation is telling you the physical market is tight now and a curve in contango is telling you it is not.

Then size for the volatility you actually have rather than the one you would like. Oil's daily range is frequently 2% to 3% of price, and it gaps on Sunday opens. A stop placed at a chart level without reference to that range is a stop that gets taken out by noise. Work the distance out from ATR first, then convert it into contracts with the position size calculator, and check what the overnight financing costs if you intend to hold it for a week on the profit calculator.

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Written and reviewed by the MarketPro research desk

MarketPro is a trading-signal and trading-education app operated by Harajuku Holdings LTD (Cyprus). Our signal desk publishes and tracks every trade idea in-app, and every page here is checked against the app's live behaviour before publishing. Last reviewed 15 September 2026. How we produce signals and content · About MarketPro

FAQ

Oil Markets And Supply-Demand Drivers: questions

What time is the weekly oil inventory report?

The US Energy Information Administration publishes its weekly petroleum status report on Wednesdays at 10:30 US Eastern time, which is 15:30 in London during British Summer Time. An industry body releases its own estimate the previous evening, and that number frequently moves price ahead of the official release. Both are on the calendar years ahead, so there is no excuse for being caught in an unplanned position across them.

What is the difference between WTI and Brent crude?

They are different grades priced at different delivery points. WTI is a light sweet crude delivered at Cushing, Oklahoma, so it reflects the US inland market. Brent references North Sea production and is waterborne, which makes it more sensitive to global seaborne supply and to disruptions outside the United States. The spread between them widens when US inland logistics or export capacity become a constraint.

Why does oil spike on news and then fall back?

Because the initial move prices the probability that barrels will be lost, not barrels that have actually been lost. If exports continue uninterrupted, that risk premium decays over the following days and weeks. Several conflicts in producing regions have produced double-digit spikes fully retraced within a fortnight. The distinction to draw is whether physical flows changed, which persists, or whether only perceived risk changed, which usually does not.

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