Oil just tumbled into a bear market. Here's why Trump's trade war is to blame. President Donald Trump's trade disputes with key international trade partners have claimed another victim. West Texas Intermediate (WTI) crude oil slid Thursday after slumping into a bear market the day prior, plunging by more than 20% since its late-April high. The commodity was trading near $51.70 per barrel. The severe downturn in a matter of weeks comes as oil traders fret over slowing global growth