Updates
Moments later: CNBC talking head says that traders are starting to question more openly whether Saudi can meet their pledge to cover any Iranian shortfall; Brent continues to outpace WTI; the gap continues to increase.
Original Post
Let's look at the recent chronology:
First, we all knew that Iranian oil exports would decrease under sanctions --> price up.
Second, Saudi said they could cover any Iranian shortfall --> price down.
Third, today, -- prices up. The "first" above was a given, almost a "fact." The "second" point -- well, there it is, we have differing opinions on the veracity of the Saudi reassurance.
Oil is now up about $1.50.