Customers push shopping carts while exiting a Costco Wholesale Corp. store in Richmond, California.David Paul Morris | Bloomberg | Getty ImagesCheck out the companies making headlines after the bell:Shares of Costco dipped 1% during extended trade after the company reported sales that missed analyst expectations for the fourth quarter. The wholesaler reported $47.50 billion in revenue, just shy of Wall Street’s expectation of $47.57 billion, based on a survey of analysts by Refinitiv.Net income grew to $1.09 million, or $2.47 a share, compared to the $1.04 million, or $2.36 per share a year prior.Sales at Costco stores open more than a year also grew 5.1%. In the U.S., same-store sales grew 6.2% compared to 1.9% growth internationally.Smart Global Holdings shares tanked nearly 17% after the memory chip-maker posted a fourth-quarter miss on revenue. Net sales came in at $278.4 million compared to the $285 million analysts expected, according to Refinitiv. Quarter four net sales are down 26% year over year.Their COO and CFO Jack Pacheco attributed the earnings miss due to “weakness in [their] supply chain services business.”Avaya shares surged 18% after the company announced a $500 million share repurchase plan, $250 million debt pay-down, and strategic cloud computing partnership with RingCentral. RingCentral will now be the exclusive provider of UCaaS solutions to Avaya, contributing $500 million to its partnership with Avaya along with $125 million in preferred stock convertible at $16 per share.RingCentral’s shares, meanwhile, rose 9%. Avaya’s stock reached a new year-to-date low earlier Thursday.Etsy shares rose 1.2% after the bell following Nomura Instinet’s initiation of the e-commerce company with a Buy rating at a $70 price target. New programs like free shipping should boost Etsy’s margins and market-cap, Nomura Instinet said.CNBC’s Jasmine Wu contributed to this report.