America went to Saudi Arabia and told them to dump oil to put pressure on Iran and the Russians. Saudi Arabia was happy to do it because they also wanted to slow down fracking in the U.S. You had this artificial geopolitical event, which drove the price in oil down. If you get out the charts, you can see the drop almost exactly coincided with American negotiations with Iran.
Jim Rogers is a smart investor who co-founded the Quantum Fund with George Soros in 1973. By 1983 the fund gained more than 4000 percent.