Oil prices hit a recent high in early October but have fallen sharply since. US crude, for example, had its weakest month in a decade as the price recently plummeted 22%.
The global declines are due to a number of factors, mostly related to supply and demand. A strong U.S. Dollar and slowing economic growth have played a role in reducing demand. High output from Saudi Arabia and US sanction exemptions on Iranian oil bolstered supply.
OPEC has reduced output since November, which has played a role in the recent price increase. However, global prices are still much lower than the highs seen in October.