Wall Street saw some turbulence on Monday, as major benchmarks initially rose, gave up their gains, and then continued to oscillate up and down throughout the day before finishing lower. Many investors paid most of their attention to massive corporate mergers, including deals involving some of the largest U.S. wireless carriers, as well as giants in the oil refinery world. Nevertheless, not all stocks benefited from good news, and some individual companies got hit with setbacks. First Solar (NASDAQ:FSLR), Arconic (NYSE:ARNC), and Celgene (NASDAQ:CELG) were among the worst performers on the day. Here's why they did so poorly.

First Solar gets stuck in the shade

Shares of First Solar fell 9% as the solar specialist gave up the gains it had enjoyed late last week after reporting its first-quarter financial results. Despite the company's revenue plunging 36% from year-ago levels, net income soared, producing earnings that were fully eight times higher than they were in the first quarter of 2017. Some analysts following the stock also looked kindly on First Solar, with UBS today boosting its price target by $13 to $94 per share and repeating its buy rating on the company. Yet some investors still seem to be nervous about the company's ability to keep expanding at a breakneck pace. Right now, there doesn't seem to be much fundamentally to justify those fears in the long run, making today's drop seem out of place.

Four long rows of solar panels in a semi-arid landscape with power transmission lines in the background.

Image source: First Solar.

Arconic's guidance disappoints

Arconic stock plunged nearly 21% after the specialist in the production of aluminum and other lightweight metals issued its first-quarter financial report. Sales for the company were up 8%, but a faster rise in costs of goods sold ate away at margin, and that helped contribute to a drop of more than half in Arconic's net income. Even though that decline was largely due to a one-time adjustment last year following Arconic's spinoff, the aluminum specialist also cut its guidance for full-year earnings by nearly 20%. Unless aluminum prices recover quickly and the uncertain tariff situation resolves itself soon, Arconic could be vulnerable to further losses.

Analysts aren't impressed with Celgene

Finally, shares of Celgene lost 4.5%. The biotech giant got negative comments from analysts at Morgan Stanley, who predicted that it could take several years for Celgene to move forward with plans to file for approval from the U.S. Food and Drug Administration for its multiple sclerosis candidate drug ozanimod. Celgene already tried to file for FDA approval, but the regulatory agency took the unusual step of issuing a refusal to file letter that said the biotech company hadn't provided enough information for a full review. Investors had hoped that any delay in submitting a revised application would be short, so Morgan Stanley's suggestion that it could take a lot longer for Celgene to recover from its mistake wasn't well-received by shareholders.