Why the gap appears

Readers checking the oil price on Friday 30 October may have seen two very different Brent crude prices quoted at the same time: one near $116 a barrel and another near $112. Both were real quotes, but they were for different delivery months.

Brent's expiring December contract rose 1.04% to $116.08 a barrel at 03:23 GMT, Invezz reported, citing Reuters figures, while the more actively traded January contract reached $112.19. US West Texas Intermediate advanced 1.34% to $103.37 at the same time.

Oil futures trade in monthly contracts, and the contract that is about to expire can move differently from the next one. As traders roll their positions from December into January, the headline price steps down when the quote switches to the later contract, even though neither contract has fallen by that amount.

Morningstar's week-in-oil summary, published 30 October, likewise noted that the most active Brent contract, for January delivery, traded above $113 a barrel on Friday, while West Texas Intermediate hovered around $104. Both benchmarks were on track for weekly gains.

What actually moved on Friday

The underlying story on Friday was higher, not lower, oil. Prices climbed as renewed threats of US strikes against Iran and attacks near Middle Eastern shipping routes revived fears of supply disruption, Invezz reported.

Brent was heading for an October gain of nearly 11%, its fourth consecutive monthly advance, while West Texas Intermediate was on course to rise around 14%, according to the same report. The $4 gap between the December and January Brent quotes is therefore a calendar effect to read alongside those gains, not a separate price fall.

Sources: Invezz (Reuters figures) | Morningstar (Dow Jones Newswires)