After the excitement around Opec agreeing oil supply cuts with Russia and other non-members at the end of last year, attention in 2017 has quickly shifted to the next key question: will they actually deliver all the promised cuts? A group of companies believe that they are positioned to deliver that answer, trumpeting their years of experience tracking global oil flows, using everything from modern satellite technology to an old-fashioned network of sources on the ground. Resting on their analysis will be billions of dollars worth of oil trades, with their clients stretching from some of the world’s largest hedge funds to Opec members themselves, all hoping to gain an edge over their rivals. Matt Smith, director of commodity research at one tanker-tracking firm, Clipper Data, says his company uses a combination of satellite monitoring — the vast majority of the world’s oil tankers now carry trackers designed to help avoid collisions — and relationships with companies that collect the port agent bills. More importantly, Mr Smith says, is their use of historical modelling, which allows them to assess the type and quantity of crude likely to have been loaded on to individual vessels.