All figures kb/d, computed from the model tables. Full call: the Dashboard.
Geopolitics
Iran watch: Iran's sanctioned barrels still sail, and China buys most of them. The shadow fleet is the swing tanker supply on the sour market.
Hormuz watch: A Hormuz disruption is the fastest way sour barrels reprice, and Western Canadian Select (WCS) prices as sour.
Red Sea: Rerouting around the Red Sea lengthens voyages and raises freight, which changes what it costs to move a barrel across oceans.
Russian refineries: Russian refinery outages push more Russian crude onto export routes, where it competes with the sour barrels WCS buyers bid on.
China imports: China is the marginal buyer of the world's sour barrels, including Iranian and Russian grades that compete with WCS.
OPEC & Middle East: Organization of the Petroleum Exporting Countries (OPEC+) quota decisions set the Middle East sour supply that WCS competes against.
Trump watch: Tariffs and policy moves from Washington hit Canadian differentials directly.
The global sour barrel: Dubai, Mars, and Merey are the sour benchmarks WCS is priced against. Their spreads are the arb that matters.