Check out the companies making the biggest moves midday. Apple — Shares of the iPad maker jumped 3.26%, leading the rebound in the Nasdaq Composite. The rally came after Bank of America upgraded Apple to buy from neutral. The bank cited a stronger multiyear iPhone upgrade cycle as well as higher growth in services as Apple better monetizes its installed base of customers. Humana — Shares tumbled 7.99% after the health insurance company said in a filing it experienced higher-than-expected medical costs in the fourth quarter, which could also weigh on its 2024 forecast. Humana also said it believes the emerging trends are affecting the industry more broadly. Shares of UnitedHealth fell nearly 3%, while CVS Health lost about 5%. MDC Holdings — The homebuilder soared 18.37% after Japanese homebuilder Sekisui House reached a $4.95 billion deal to buy MDC. Sekisui House will pay $63 per share in cash, nearly 19% above MDC’s closing price Wednesday. Taiwan Semiconductor Manufacturing — U.S.-listed shares of the semiconductor company popped 9.79% on the back of a fourth-quarter profit and revenue beat . Taiwan Semiconductor also said it expects 2024 to be a “healthy growth year.” Shares of some of the company’s major customers rose, too, with Nvidia , Apple, Qualcomm and Advanced Micro Devices up at least 2% each. Hertz — The stock jumped 7.54% after being upgraded to overweight by Morgan Stanley. The investment bank said the rental car company’s decision to sell about 20,000 electric vehicles from its fleet should help boost the stock. Spirit Airlines — Shares tanked another 7.17% as fallout from the budget airline’s blocked proposed merger with JetBlue continued to weigh on the stock. Spirit, which plunged 60% the first three trading days of the week, was also downgraded by Citi on Thursday to sell from neutral. Fastenal — Shares gained 7.18% after the distribution giant exceeded Wall Street expectations for the fourth quarter. Fastenal earned 46 cents per share on revenue of $1.76 billion, while analysts polled by StreetAccount forecast 45 cents per share on $1.75 billion in revenue. Fastenal said it got a boost to unit sales from growth at on-site locations as well as currency tailwinds. First Horizon — The regional bank added 5.06% after First Horizon beat earnings expectations in its fourth quarter. Adjusted earnings per share were 32 cents, versus the 27 cents expected from analysts polled by StreetAccount. Net interest income and net interest margins also came in higher than expected. Discover Financial Services — Shares slipped 10.8% after the financial services company reported fourth-quarter earnings per share of $1.54 postmarket Wednesday, missing estimates of $2.50, per LSEG, formerly known as Refinitiv. Birkenstock — The German shoe company shed 7.72% after warning that its full-year earnings will come under pressure as it pursues a global expansion. It was Birkenstock’s first earnings report as a public company. KeyCorp — The Cleveland-based bank dropped 4.62% after reporting fourth-quarter adjusted earnings per share of 3 cents, down from 38 cents a year prior. Net interest income also fell year over year, to $928 million from $1.2 billion in the fourth quarter of 2022. Microchip Technology — The tech manufacturer added 3.38% after being upgraded to outperform from peer perform by Wolfe Research. The firm said a lot has been done to de-risk the stock heading into its fiscal third-quarter earnings report. Plug Power — Shares of the beaten-down fuel cell company dropped 11.52% after Morgan Stanley maintained its underweight rating and $3 price target. Plug will need to use a substantial amount of its $1 billion at-the-market equity program it announced after market close on Thursday, Morgan Stanley said. Grab Holdings — Shares rose 2.74% after JPMorgan upgraded the Singapore-based ride-hailing and food delivery app to overweight. As catalysts for the upgrade, the bank highlighted an attractive valuation and improving delivery margins. Kinder Morgan — Kinder Morgan shares slid 1.42% after the natural gas pipeline operator reported fourth-quarter revenue of $4.04 billion, missing the LSEG consensus estimate of $4.41 billion. — CNBC’s Lisa Han, Samantha Subin, Alex Harring, Yun Li, Pia Singh and Sarah Min contributed reporting.