All ICIS-published assessments in the crude oil market are so-called “market closing” assessments. That is, they are intended to represent the tradable value of a particular crude grade at the time commonly agreed by the marketplace to represent a daily physical market “close”.
A closing value price assessment takes into account:confirmed deals, bids and offers; market direction; and market relationships with other like grades and related derivative instruments, where relevant, at the time of the close of business for each region.
The value published is intended to reflect the real transactable value of a commodity at the point of close. As such, bid and offer information at the close would take precedence over transactions done earlier in the day. Where a confirmed deal is done for the same grade and loading range as confirmed bids and offers, and when all are declared to the market simultaneously, the deal will
take precedence over the bids and offers.
To find out more World Crude Oil Methodology August 2013