Take a look at the companies making headlines in midday trading. Micron Technology, chip stock — Shares of Micron Technology soared nearly 13% after the memory chip maker issued strong guidance as the rise of artificial intelligence increases demand for its products. Other chip stocks followed suit, with Applied Materials, ASML Holding and Lam Research each up about 4%. Super Micro Computer — Shares of Super Micro Computer plunged more than 12% after the Wall Street Journal reported that the Justice Department had launched an investigation into the maker of artificial intelligence servers. Southwest Airlines — Shares rose 11% after the airline raised its third-quarter revenue forecast and authorized $2.5 billion in stock buybacks. The company also announced several changes to its business model in an attempt to fend off activist Elliott Investment Management and convince investors it is boosting profits and growing revenue. Starbucks — The coffee chain gained nearly 2% after Bernstein upgraded its shares to outperform, citing confidence in the company’s new chief executive. NRG Energy — Shares of NRG Energy rose 1.6% after the energy company raised its full-year guidance. NRG Energy currently expects adjusted EBITDA to range from $3.53 billion to $3.68 billion. GE Healthcare – Shares of GE Healthcare fell more than 1% after UBS downgraded the healthcare technology company to a sell rating from neutral, citing growth risks in its China business. Jefferies Financial — The investment bank lost more than 2%. The company’s fiscal third-quarter earnings were 75 cents per share on revenue of $1.62 billion, missing FactSet estimates. CarMax — The used car retailer beat fiscal second-quarter sales estimates, sending its shares up nearly 6%. The company also reported a 5.1% increase in retail used sales. Jabil — Shares of Jabil rose more than 11% after the manufacturing solutions provider reported stronger-than-expected quarterly profit and revenue. Jabil reported earnings of $2.30 per share, beating the FactSet forecast of $2.22 per share. Revenue of $6.96 billion also beat expectations. NEW YORK COMMUNITY BANK — Shares of the regional bank rose nearly 8% after Barclays upgraded shares of the regional bank to overweight from equal weight. Barclays said the New York community bank has done the “heavy lifting” of restructuring and has good risk-reward prospects going forward. Bilibili – Shares of the U.S.-listed Chinese internet company rose 12.5% after Goldman Sachs upgraded its rating to “buy” from “neutral”. Goldman Sachs said the company is starting a profit growth cycle. Sonos – The home audio company fell 4.3% after Morgan Stanley downgraded its rating to underweight from overweight. Analyst Erik Woodring believes the backlash to the company’s May app redesign will hit the company’s top and bottom-line metrics more than the market is currently pricing it in. rose nearly 5% in anticipation of fourth-quarter results. The company also issued strong guidance and raised its quarterly dividend. —CNBC’s Jesse Pound, Yun Li, Alex Harring, Pia Singh and Hakyung Kim contributed reporting