What do you call someone who is always wrong? [closed]

If such a person is reliably always wrong, you may call them a contra-indicator. This is sometimes used in financial markets. You may not know what to do, but then you look at what the contra-indicator does, and you do the opposite for virtually guaranteed success.

Examples:

https://realmoney.thestreet.com/articles/06/10/2016/cramer-ultimate-oil-contra-indicator-has-spoken

https://www.guggenheiminvestments.com/perspectives/global-cio-outlook/davos-as-contra-indicator

https://finance-market-news.com/tag/goldman-contraindicator/

I'm not sure there is anything that describes someone who is ALWAYS wrong.

But someone who has a tendency always to be wrong, or show bad judgment, is sometimes described as wrong-headed.