This is the story as I understand it. Caesars Entertainment used to be called Harrah’s Entertainment. Harrah’s Entertainment was a publicly traded company with the stock ticker HET.
Instead of calling Harrah’s Entertainment they called Harrah’s HET. OK, fine. That makes sense. When Harrah’s went private a few years ago they changed their name to Caesars Entertainment. When Caesars Entertainment went public they chose the stock ticker CZR.
I’m not sure if people are calling CZR by the name CET or if it’s actually short for something else. As far as I can understand there is no CET in the casino business unless you’re talking about Central Securities.