Traders work on the floor of the New York Stock Exchange (NYSE) in New York, U.S., December 27, 2018.Eduardo Munoz | ReutersCheck out the companies making headlines midday Monday:Boston Beer — Shares of Boston Beer rose 2% after Guggenheim raised its price target to $462 from $449 per share, citing strong growth from spiked seltzer brand Truly. While privately-owned hard seltzer brand White Claw is still the category leader, Truly is beating Guggenheim’s growth estimates with no signs of slowing down.Amazon — Amazon shares dipped about 1% after an analyst at Morgan Stanley cut e-commerce giant’s price target to $2,200 from $2,300. The analyst said the target reduction was due to Amazon’s one-day shipping, but noted this will be a long-term benefit for the company.Chewy — The pet-food online retailer was upgraded to buy from neutral by an analyst at Nomura Instinet, sending Chewy shares up 4.2%. The analyst said concerns about Chewy’s profit margins are overblown, noting: “We remain confident that the core business continues to perform.”Akcea Therapeutics — Shares of Akcea Therapeutics plunged 20% after the company announced the departure of CEO Paula Soteropoulos. President Sarah Boyce and COO Jeff Goldberg will also leave the company. An analyst at Wells Fargo Securities downgraded Akcea to market perform from outperform citing Soteropoulos’ departure. The analyst also slashed his price target to $24 per share from $44. The stock traded around $17.90.Overstock.com — Overstock shares dropped 15.1% after the online retailer said it expects third-quarter adjusted EBITDA to come in flat. Overstock cited higher costs from tariffs on Chinese-made goods and “waning consumer confidence” for the weak guidance.Acadia Pharmaceuticals — Acadia Pharmaceuticals climbed 3.3% after the company released positive Phase 2 study results for Pimavanserin, a drug used to treat Parkinson’s disease psychosis.Lululemon — Piper Jaffray initiated coverage of Lululemon with an overweight rating. “We see the brand as a share gainer in a secularly growing category with accelerating opportunity in men’s and international,” according to Piper Jaffray. Lululemon shares rose 2.5%.Best Buy — Shares of Best Buy rose 1% after Morgan Stanley said the company’s push into health care could generate $11 billion to $46 billion in long-term revenue. Best Buy is shifting from just selling health care devices to now focusing on tech-enable senior care, an “untapped white space opportunity in healthcare,” the firm said.—CNBC’s Maggie Fitzgerald and Michael Bloom contributed to this report.