Ah, the stock market. A bastion of rational expectation, meticulous forecasting, and unwavering stability. Or, at least, that’s what the textbooks tell us. In the era of Donald J. Trump, however, these hallowed halls of finance often resemble a particularly chaotic game of whack-a-mole, with policy pronouncements serving as the mallet and investor sentiment as the perpetually surprised moles. The latest round of announcements, threats, and retractions from the former (and potentially future) President has, ...