API crude oil inventories: the Tuesday evening industry estimate

What the API figures are

API compiles weekly inventory data reported by member companies and other operators. It covers much of the same ground as the EIA report released the next morning: changes in commercial crude stocks, stocks at Cushing, gasoline and distillate inventories. The full bulletin is a subscription product, but the headline changes are widely reported by news services within minutes.

Because reporting is voluntary and coverage and methods differ from the EIA survey, the two sets of figures can diverge, sometimes in sign. The API number is best read as an early estimate that the EIA can confirm or contradict.

Why the market trades an unofficial number

• It is the first information about the week's balance, about eighteen hours before the official data.
• A large surprise shifts expectations for the EIA report and positions are adjusted overnight.
• When API and EIA disagree, the EIA figure usually takes over, and the Tuesday evening move can be reversed on Wednesday.
• Product figures, especially gasoline during the driving season, can matter as much as crude.

Order flow in the post-settlement session

The API release comes after NYMEX crude oil's daily settlement and before the daily maintenance break of the CME Globex platform at 4:00 p.m. Chicago. Participation is lower than in the morning, the book is thinner and spreads can widen more easily, so a moderate surprise can produce a sharp move on modest volume.

On the footprint, that shows as a release bar with a large range relative to its volume, and trade bubbles that are fewer but larger than in daytime. Whether the move holds is decided later, during the overnight session and finally at the EIA release the next morning. Treating the evening move as provisional is the realistic reading.

In Senzoukria

The API figure is not always carried as a row by the calendar feed. When it is, the News calendar describes rows naming API crude as “Oil inventory — WTI/CL driver.”, and a macro event line marks it on the chart. When it is not, set a keyword alert on words such as inventories or crude stocks: alerts ring once per matching headline, with the wire's delay of about 15 minutes.

Effort versus result is the useful lens on thin evening books: a large range on little volume (low effort, big result) says the book was empty rather than that participants were determined. The Tape Speed indicator shows how few trades carried the move.