The term “TACO,” short for Trump Always Chickens Out, has been used to describe how markets tumble on the president’s tariff threats, then rebound when he gives way.

The “Trump Always Chickens Out” meme hatched on Wall Street, went viral in Washington, and now has its own Taco Tuesday ritual. Here’s how a joke became a litmus test for trade policy. Following last week’s mainstream debut of the Wall Street-borne acronym TACO,