Image source: Qualcomm.

After a flat performance in the previous session, the stock market launched upward Wednesday, climbing on what investors perceived as positive comments from the Federal Reserve that the U.S. economy was in strong shape. Those gains didn't prevent some stocks from losing ground, with Qualcomm (NASDAQ:QCOM), Sprint (NYSE:S), and GoPro (NASDAQ:GPRO) appearing on the list of worst-performing stocks for the day.

Qualcomm dropped 9%, hitting a new four-year low as the semiconductor manufacturer faced allegations from the South Korean Fair Trade Commission that it violated anti-competitive laws. Qualcomm maintained that the regulator's allegations "are not supported by the facts and are a serious misapplication of law." Yet because the semiconductor maker gets so much of its revenue from licensing royalties, any threat to that income source is enough to concern investors, especially given how much the stock has already gotten hit recently. With Qualcomm continuing to fight with Chinese customers to ensure that it gets paid the licensing fees that it deserves, investors in the embattled tech giant could see further pressure in the near-term.

Sprint fell 9% after the telecom once again resorted to heavy promotional activity to fight against its competitors in the industry. Sprint announced what it called the "biggest wireless offer in U.S. history," offering 50% off the price of most wireless plans from its three main competitors. Moreover, Sprint said that it would cover up to $650 in switching fees, and the promotion runs through early January. Investors are concerned that Sprint's latest action will only exacerbate the price war among major U.S. carriers, leading to a race to the bottom that will hurt profits throughout the industry. With Sprint in particular having had difficulty keeping up with its competitors, it's arguably in the worst position to get through a drawn-out price war without taking serious financial damage.

Finally, GoPro declined 5% after having been down as much as 10% earlier in the trading session, hitting a new all-time low as a public company. The video-equipment maker suffered from another analyst downgrade on Wednesday, as Piper Jaffray cut its price target on GoPro stock to just $15 per share. The analyst pointed out that a decline in prices of GoPro equipment on key e-commerce sites is troubling, as are appearances on discounter websites. Even if the discounts lead to more sales, the hit to gross margin could call into question GoPro's long-term growth trajectory. Most bulls would argue that GoPro's future value should include potential profits from the video content that its users are sharing, but GoPro's plunging stock suggests that more investors are treating the company as an electronics seller rather than a budding media giant.

Dan Caplinger has no position in any stocks mentioned. The Motley Fool owns shares of and recommends GoPro and Qualcomm. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.