Friday was a relatively quiet day on Wall Street, with major indexes staying relatively close to where they began the session. Investors are getting conflicting readings on the prospects for economic growth going forward, with some signs pointing to continued strength while others call for caution. Despite the relatively calm market, some stocks suffered significant losses. American Outdoor Brands (NASDAQ:SWBI), Innovative Industrial Properties (NYSE:IIPR), and Alexion Pharmaceuticals (NASDAQ:ALXN) were among the worst performers. Here's why they did so poorly.

Tariffs eat into American Outdoor Brands' sales

Shares of American Outdoor Brands plunged 22% after the maker of firearms and outdoor equipment reported disappointing fiscal first-quarter financial results. Revenue fell 11% from the previous year's period, sending adjusted net income down by more than 80%. CEO James Debney pointed to "ongoing softness in the firearms market" that put downward pressure on the company's sales, but efforts to diversify American Outdoor Brands' business continued to gain momentum. Even so, the company has a significant supply chain in China, and so it'll be hard for it to avoid tariff impacts without taking more dramatic and potentially costly action.

Smith & Wesson tactical flashlight.

Image source: American Outdoor Brands.

Innovative Industrial loses its high

Innovative Industrial Properties saw its shares lose 12% on a tough day for many marijuana stocks. The cannabis-property real estate investment trust didn't make any direct announcements, but it's possible that the drop is connected to a recent shelf registration statement that became effective late Wednesday. Innovative Industrial has routinely done stock offerings to raise capital, and two weeks ago, the company filed to register $250 million in securities for future sale. Although more specific disclosures will be necessary to sell stock under the statement, it may be that investors are anticipating the dilution that would result from future offerings -- especially given the extensive investments Innovative Industrial has made in its business lately.

Alexion faces new challenges

Finally, shares of Alexion Pharmaceuticals fell 10%. The drugmaker faced a challenge from Amgen, which wants to offer a biosimilar version of Alexion's top-selling Soliris treatment. Soliris treats a wide variety of rare diseases, and it's been the key to the company's success. Yet despite Alexion having multiple patents on Soliris, Amgen wants to have those protections invalidated. Somewhat surprisingly, officials at the U.S. Patent and Trademark Office agreed to review the matter. Alexion hasn't lost yet, but even the need to defend itself came as a shock, and investors are afraid about even a chance of defeat and its impact on Soliris sales.

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