Wednesday was an exciting day on Wall Street, as the Dow Jones Industrial Average managed to largely bounce back from a more-than-300-point drop early in the session. Most major benchmarks finished close to unchanged on the day, as nervousness about the Federal Reserve's tenacious attitude toward maintaining its tightening stance on monetary policy overcame generally positive sentiment over third-quarter earnings and the overall pace of economic growth. Yet some bad news for individual companies proved too much for some stocks to bounce back from. Shopify (NYSE:SHOP), Fresenius Medical Care (NYSE:FMS), and Tilray (NASDAQ:TLRY) were among the worst performers on the day. Here's why they did so poorly.

Shopify deals with China fears

Shares of Shopify finished lower by 6% as the e-commerce storefront and services provider's investors reacted to reports that the Trump administration might make a policy move that would potentially deal a blow to a wide swath of the online retail industry. The White House could withdraw from a treaty that gives China the right to ship packages to the U.S. at discounted rates, furthering the president's recent efforts to put pressure on Chinese trade. Given how many e-commerce retailers import goods from China, Shopify shareholders worry that the resulting financial hit could carry over to their company. Even though stock analysts at Baird thought the move didn't make sense, investors nevertheless remained concerned about the potential impact on what has been extremely strong growth at Shopify.

Shopify logo, with green bag with letter S on it.

Image source: Shopify.

Fresenius looks less healthy

Fresenius Medical Care stock dropped 17% after the provider of dialysis products issued some downbeat guidance in its preliminary release of third-quarter financial results. Fresenius cut its 2018 targets for net income growth to a range of 11% to 12%, down from the previous range of 13% to 15%. The company also expects comparable revenue growth of just 2% to 3%, rather than the original expectation for 5% to 7%. Fresenius blamed its bottom-line woes on a host of factors, ranging from weakness in its core dialysis services business to Argentina's hyperinflationary environment and the company's need to make campaign contributions to fight state ballot initiatives to put profit limits on providers of dialysis treatment. Fresenius hopes to see underlying growth trends reassert themselves, but for now, investors need to get used to at least a temporary hiccup for the company.

Tilray eases lower on Canada's cannabis legalization day

Finally, shares of Tilray fell 6.5%. Canada made history by legalizing cannabis products for recreational use, with today being the effective date for legislation that was passed earlier this year. Investors have waited for months to see how Tilray and other marijuana stocks would perform as the Canadian market opened for business, and early reports showed solid demand from customers. Yet concerns about overvaluation linger, and it could take months for Tilray to develop a long enough history of sales for investors to assess fairly whether the cannabis company deserves the valuation its early shareholders have given it.

Dan Caplinger has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Shopify. The Motley Fool has a disclosure policy.