In this April 4, 2015 file photo, Iranian and U.S. banknotes are on display at a currency exchange shop in downtown Tehran, Iran. Iran's currency is continuing its downward spiral as increased American sanctions loom, hitting a new low on the thriving black market exchange. The Iranian rial fell to 112,000 to the dollar on Sunday, July 29, 2018, from 98,000 to $1 on Saturday. (Photo by Vahid Salemi/AP Photo)
