Here are the known and unknowns so far:WHO'S IN THE PRICE CAP COALITION? Britain said Thursday it could ban countries from using its services to transport Russian oil purchased for a price exceeding the cap. WHAT WILL THE PRICE CAP LEVEL BE? Moscow could end up cutting production as a result, which would apply upward pressure on global oil prices. Worries about potential sanctions, even if unfounded, can cause traders to avoid deals, another factor that can boost oil prices.

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