Chart of Mattel Inc. Stock (MAT) – Source: TheTechnicals.com and TradingView

Shares of iconic toy maker, Mattel (MAT), plunged a whopping 18% on Friday. It was the worst single-day loss in almost two decades. The company issued worse-than-expected full-year guidance for 2019 on Friday. This includes flat sales for the year (when adjusted for currency) as well as EBITDA far lower than consensus analyst expectations. This disappointment comes only around a week after Mattel’s stock gapped up sharply on strong earnings and sales posted for Q4 2018. The chart above shows the earnings gap up, followed by the plunge on dismal guidance.

Big Stock Losses Amid Raging Bull Market

Mattel follows in the footsteps of Coca-Cola (KO), which just a day earlier had its own worst single-day loss since the 2008 financial crisis. (See also: Coca-Cola Stock (KO) Gets KO’d After Earnings). Sizable stock plummets like what Coca-Cola and Mattel experienced in the latter half of the past week are especially notable because the overall market has been on a sharp rally since late December.

The S&P 500 is now a full 18% above its December 24 low. So even though we’re in an undeniable bull market so far this year, single stock performance is not necessarily reflective of market trends at large. It’s called unsystematic risk. Just another reason to exercise increased caution when investing in individual stocks.