Price of a stock halfed today (on a Saturday)

So I am holding certain stock in my live account and today I noticed that it’s value was sliced in half, down to $9.01, even though it was $18.02 at close on Friday 5pm. The ticker is AMC. Btw, I am familiar with the AMC Preferred Equity dividend being distributed but I am somewhat concerned that my account is not showing the new ticker and yet the value of my existing position is cut in half arbitrarily. Any idea why is that? There is nothing else showing up in my account that would explain the automatic price reduction.

Stock split. Well, similar…