Check out the companies making headlines in premarket trading. Affirm — The fintech provider of “buy now pay later” services rose 2% after an upgrade to hold at Jefferies on Tuesday. The upgrade was underpinned by “recent evidence of stabilizing cost of capital and capital markets activity, stabilizing (if not improving) credit performance, and ongoing momentum in adoption rates for BNPL.” Boeing — The maker of 737 Max jetliners gained about 2% premarket after an upgrade to outperform at RBC Capital Markets. Analyst Ken Herber said the 2024 outlook for Boeing is more favorable as demand in both the company’s commercial and defense segments grows more sustainable. Crocs — The maker of iconic, soft footwear rose more than 2.3% on the heels of an upgrade to strong buy at Raymond James on Tuesday. Analyst Rick Patel is more confident on Crocs’ business structure heading into 2024, and thinks the stock’s price-to-earnings ratio is “highly discounted given our expectation of moderate revenue growth.” Carlyle Group — The private equity asset manager with almost $400 billion under management climbed more than 5% premarket after S & P Dow Jones Indices added it to the S & P Midcap 400 index effective premarket Thursday. nLIGHT — Shares of the maker of semiconductor lasers, fiber lasers and optical fibers gained more than 4% after an upgrade to speculative buy at Benchmark. The firm highlighted a new army contract worth $35 million to produce a high energy laser, which “could result in orders which we estimate could be up to dozens of laser systems in 24-to-36 months time.” Glaukos Corporation — Shares climbed 2.4% after Truist initiated coverage of the medical device stock with a buy rating. Analyst Samuel Brodovsky said Glaukos could see revenue growth expand to 20% or more in 2025 alongside improved profit margins. Shopify — Shares of the e-commerce platform fell nearly 3% premarket after Piper Sandler cut it to underweight from neutral. The Wall Street firm said the shares hold “an untenable valuation” because consensus growth and profit expectations are too aggressive. — CNBC’s Samantha Subin, Yun Li and Jesse Pound contributed reporting Correction: The Carlyle Group will be added to the S & P Midcap 400. A previous version misstated the index.