Oil prices jumped on Monday as hopes for a Washington-Tehran deal over the Strait of Hormuz faded and the US's Strategic Petroleum Reserve fell below 300 million barrels, hovering at its lowest level since the 1980s. The SPR fell by 6.1 million barrels in August, reaching its lowest point since 1983, with inventories at 298.7 million barrels, according to data from the Department of Energy. Read more: What's the Strategic Petroleum Reserve, and can it help lower gas prices? We are just watching Iran with its huge inflation and the fact they have no money." Click here for in-depth analysis of the latest stock market news and events moving stock pricesRead the latest financial and business news from Yahoo Finance