Strategy Analytics' Linda Sui told CNBC that the slump was across every price category, and not just premium models.

As you might guess, March isn't looking much better. The coronavirus outbreak has reached Europe and North America in earnest, leading to more wary customers and store closures. China appears to be recovering, but the smartphone industry could be in for significant pain until it's clear the pandemic is on the decline elsewhere. And from all indications, that might not happen for a while.