November 8, 2016 was a memorably tumultuous night for both Donald Trump and Hillary Clinton, but it was also one in which the stock market showcased how sensitive it was to surprises and the political temperature of the country by nosediving dramatically. Since then, the market has recovered. But on Monday, a simple artificial intelligence program -- a bot -- began tracking Trump's personal Twitter account to see if the president's tweets are a reliable predictor of stock prices in the American economy. NPR's Planet Money -- the organization's bi-weekly economics podcast -- wondered if it could take Trump's volatile tweeting and use it to its advantage to make investment decisions. When he tweets about a company, I trade stocks.