OPEC and Russia agree to extend oil cuts through end of 2018

OPEC and Russia have officially agreed to extend production cuts by nine months, through the end of 2018, per Bloomberg. Nigeria and Libya, which were previously exempt from the cuts, have also agreed to enter the deal for the first time. Their addition is a victory for OPEC, as their rising production output has been a challenge to the group's efforts to tighten the market.

Why it matters: The very existence of this Saudi-Russia cooperation signals the extent of the shadow the U.S. shale industry has cast over the oil market in recent years.