Image source: Cliffs Natural Resources.

Wednesday wasn't a strong day for the stock market, with major market benchmarks falling as much as almost half a percentage point on the day. Weakness in the energy patch was especially notable as crude oil prices pulled back from their recent efforts to bounce higher from the $40 per barrel mark. Earnings season also continued to have a dramatic impact on stocks, and although some companies reported solid results that sent their shares higher, plenty of others gave their investors less than encouraging news. Among the poorer-performing stocks on the day were SunPower (NASDAQ:SPWR), Myriad Genetics (NASDAQ:MYGN), and Cliffs Natural Resources (NYSE:CLF).

SunPower warns that profits might end up in the shade

Solar specialist SunPower plunged more than 30% after it warned that its third-quarter and full-year results wouldn't be able to live up to investors' expectations. The company surprised some investors by noting that a pickup in solar-power system investments from power companies in the U.S. could lead to a temporary spike in sales that won't be sustainable, leading to decreased revenue opportunities in the years to follow. Bulls and bears disagree about whether SunPower will successfully navigate a cyclical downturn, but most seem to concur that the fact that a downturn is coming was a shock to investors generally. Many of SunPower's peers are also taking hits as a result of the news and the implications for the industry as a whole.

Myriad fails the test

Myriad Genetics fared even worse, losing a third of its value in the wake of its fiscal fourth-quarter report. The maker of genetic testing and diagnostics products offered earnings guidance that was as much as 40% below what investors had expected, and high competition in the company's testing business for hereditary cancer is hurting Myriad to a greater extent than previously anticipated. Myriad has several new products coming out in the near future, but the question investors are asking is whether the company can profit from them long enough and to a great enough extent to justify the investments it has made in their success. Several analysts also downgraded the company's stock, and Myriad will have to surpass its own downbeat guidance in order to prove them wrong.

Cliffs Natural raises cash

Finally, Cliffs Natural Resources fell 8%. The producer of iron ore announced a new secondary offering of stock, saying it intends to raise $300 million through the sale of shares in order to help it pay down debt. In particular, Cliffs has outstanding senior notes that come due in January 2018, and the company said it would focus on using net proceeds from the offering in order to meet its obligations under those notes. The move is just the latest effort from the iron-ore producer to restructure its debt and weather what has been terrible conditions in its industry for quite a while.

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