The Iranian Rial has plunged 50% on unofficial markets since April due to a weak economy and high demand for U.S. dollars as Iranians prepare for U.S. sanctions, scheduled to begin August 7th. Iran’s government attempted to fix the exchange rate in April and crack down on black market traders, but the attempts were unsuccessful and the government has softened its restrictions. Responding to the looming sanctions, the Iranian government has announced a series of price and tax incentives to private investors who will take over unfinished state projects. U.S. sanctions are projected to reduce Iran’s oil exports by up to 2/3rds.
Source: Iran’s currency plunges to record low as US sanctions loom | News | Al Jazeera