Oil traders fear that a U.S.-Iran nuclear deal, which could come as early as this week, could pave the way for exports of Iranian crude to already-glutted world markets. If so, that could send WTI prices tumbling below $50 a barrel, a level not seen since April.
Traders are also concerned that a surprise uptick in weekly U.S. oil inventories last week may signal the start of another build in U.S. supplies once summer driving season peaks.