Walgreens (NASDAQ:WBA) shares were hit hard on Thursday as the company’s entry to the Dow Jones Industrial Average was overshadowed by Amazon’s (NASDAQ:AMZN) recent foray into the pharmaceutical industry.

The pharmacy chain was hoping that its entry into the index would signify a step forward for the pharmaceutical industry, but Amazon’s decision to acquire PillPack caused Walgreens to lose market share ahead of Friday’s action. PillPack is a business that’s aimed at consumers who take multiple medications.

Plus, Walgreens is also experiencing this setback because the drug store chain has become growingly reliant on its pharmacy sales to increase sales and profits. The company recently unveiled its fiscal third quarter earnings, which were ahead of analysts’ expectations, but the company experienced weakness in its retail division, which led several analysts to downgrade the stock.

The retail segment mostly consists of the company’s front-of-the-store items that consumers grab when they’re filling prescriptions, such as hair products or sodas. Walgreens’ revenue excluding pharmacy sales were down about 3.8% last quarter in stores open at least a year compared to the company’s year-ago figures.

The figure had declined by about 2.7% year-over-year during the previous quarter.

WBA stock was down about 9.9% by the end of Thursday, but the stock managed to recover slightly after the bell, gaining 0.5%.