Incidentally, I don't refer to other types of mentally impaired people as "retard". The word has a negative connotation, similarly to "moron".
Both terms obviously should be received negatively, they are insults. That's how insults work.
I am happy to refer to more groups, not only Tesla investors, as retards too. I'll leave this as an exercise to imagination.
I'm very sorry for the person you choose to be, then