Check out the companies making headlines midday Wednesday:
Signet Jewelers — Shares of Signet Jewelers rose 0.5 percent after the diamond retailer reported better-than-expected quarterly results. Signet reported earnings of $3.96 per share, 14 cents higher than expected, and revenues of $2.155 billion, $11 million higher than expected.
Verizon — Shares of Verizon Communications rose 0.6 percent — erasing earlier losses — after the telecommunications company announced it will be activating its 5G mobile network in Chicago and Minneapolis. Verizon also said add the service to 30 additional markets this year. The 5G network would give users speeds of roughly 10 times faster than current LTE network speeds.
Caterpillar — Caterpillar shares fell as much as 1.3 percent after an analyst at Deutsche Bank downgraded the stock to hold from buy. The analyst cited collapsing "synchronized global growth," noting: "China Land Cycle is rolling over, ... Europe is slowing more than expected and the US is oversaturated with construction equipment."
Advanced Micro Devices — Shares of Advanced Micro Devices shot up 8.5 percent after Nomura Instinet initiated coverage with a buy rating and a $33 per share price target. Nomura cited AMD's high revenue growth and rapid improving profitability.
GameStop —The video game and electronics retailer fell over 4 percent after the company's fiscal fourth-quarter revenue missed expectations. GameStop reported $3.06 billion in revenue versus a Refinitiv estimate of $3.28 billion. The company also warned of a potential upcoming loss in the fiscal first quarter of 2019.
Usana Health Sciences —Usana Health Sciences dropped about 3.5 percent after the company announced preliminary first quarter results that missed expectations. A lack of promotional activity and the impact of China's review of direct sellers is to blame, the company said in a release.
StoneCo — Shares of the Brazilian payments software company fell more than 8 percent after pricing its secondary stock offering at $40.50 per share. The company is selling 19.5 million shares in the offering, more than the 17.9 million indicated in a prospectus.
Urban Outfitters — The retailer's stock rose more than 3 percent after DA Davidson upgraded it to buy from neutral. The firm cited improving fundamentals for Urban Outfitters, noting: "Management has been methodically laying the foundation for a best-in class brand apparel company that could thrive under the shifting retail paradigm."
GrubHub — Shares of GrubHub rose 0.4 percent after BTIG initiated the food delivery company as buy with a price target of $95 per share. The firm cited optimism about GrubHub's growth in restaurant partnerships.
—CNBC's Nadine El-Bawab and Jessica Bursztynsky contributed to this report.