Looks like the Hellcat has comp and it cost less!!!

Why is it that NEW Mopars depreciate the most when compared to Fords or Chevies?

Supply and demand. Let's be honest, there are far more of either Chevy guys or Ford guys than there are MoPar guys. SO, when it comes to these specialty cars, there is a lower demand for them, hence, greater depreciation, faster than the Fords and Chevies.

It has nothing to do with quality, or even power, it has to do with choice. Even when Chrysler was a force in the automobile industry, GM and Ford both outsold Chrysler, a few times over.
Even when it comes to car enthusiasts, GM/Chevy fans outnumber MoPar fans a few times over, as do Ford fans.

Lower demand, higher and faster depreciation, lower prices is the rule, and there is always the exception to be had, though.