What happened

Shares of Costco (COST -0.24%) took a hit on Friday. The stock declined as much as 7.5% and finished the trading day down about 4.1%.

The warehouse club stock's decline was likely primarily due to growing fears about the COVID-19 coronavirus' impact on the global economy.

A cart in the aisle of a warehouse club

Image source: Getty Images.

So what

Highlighting the continued bearishness in the market on Friday, the S&P 500 index declined 0.8%, bringing the market's total decline this week to 11.5%. Shares of Costco tracked similarly throughout the week, falling about 12%.

Some investors may have felt that it was a good time to take profits on Costco. Shares have risen sharply over the past year. Even including this week's pullback, the stock is up 29% over the past 12 months. This compares to the S&P 500's 5.8% gain over this same time frame.

Now what

Investors have high expectations for Costco, as same-store sales have consistently risen at robust rates. January same-store sales were up 6.6%.

Costco will report its February sales and its fiscal second-quarter results next week, after market close, on March 5.