The shares shed 12.8% at US$27.53 in opening deals, as investors got shot of the stock faster than an unwanted Christmas present.
The Barbie dolls maker said net revenue in the fourth quarter of 2016 was down 8.3% year-on-year to US$1.83bn, which was well short of the US$1.96bn the market had been expecting.
The company said sales had been hit by increased competition and weak demand in North America.
Sales in North America were down 7% from a year earlier.
The flagship Barbie doll product saw sales slide 2% from the same period the previous year, although stripping out foreign exchange rate movements would have resulted in a 1% gain.
The company told analysts that the retail channels are currently stuffed full of stock, which would affect the current quarter’s sales.