Tariffs are back in the mindset of investors after the U.S. imposed 50% tariffs on some Canadian exports. Canada followed up with retaliatory tariffs. Tom White turns to the implications they have on the global trade picture as the U.S. grabbles with headwinds with Iran and the Strait of Hormuz. The international tensions come as Nvidia (NVDA) releases earnings Wednesday in what's expected to be the biggest report of the quarter.