Given how often Trump tweets about specific companies, does this offer opportunities to make (or lose) money on them?

There is, in fact, a bot which already does this. According to NPR, an advertising company in Texas called T3 has developed a bot which continuously monitors tweets made by Trump. It checks to see if the tweet has the name of a publicly-traded company (say, Delta Airlines), and if so, performs a sentiment analysis to see if Trump’s statement is positive or negative about the company. If it’s negative, the bot borrows stock in the affected company, sells it before the price drops, then buys it up again once the price bottoms. Since these stock movements tend to be rather short-lived, and the bot acts in a matter of seconds, it makes (or loses) its money very quickly. It also doesn’t make a lot–5% or so.

Currently, the bot’s profits are donated to the American Society for the Prevention of Cruelty to Animals. It is likely that trading firms are already quietly using similar technology to make money themselves, though.

Let us take a moment to reflect on an environment in which the President popping off about a random company ends up making somebody money (and probably costing someone else some money, too). We live in strange times.