There once was a time when investors had high hopes for Cardano (ADA), but that seems to be quite a long time ago now. Cardano has been on a dangerous downward spiral in the last year, with ADA losing 81.51% of its value in the last 12 months, as of December 30. The coin is all the way down to $0.24, and it's possible that it could plunge below 20 cents in the near future.