Oil prices could fall because of the nuclear deal with Iran.
The plan does not allow Iran to sell any more oil right now, but it does open the door for a future deal that would eventually allow Iran to increase production.
If that happens, it would put more oil on the world markets and help bring the price down, which would lead to lower prices at the pump.
But analysts say if the deal falls apart, the cost of oil could shoot back up again. Oil and gas prices have already been falling in the last few months.