Check out the companies making headlines before the bell: Levi Strauss — The jeans maker surged 11% after the company reiterated its full-year outlook. However, Levi noted that it excludes any impact from the White House's tariffs. The company also posted first-quarter adjusted earnings of 38 cents per share, which was 52% higher versus the year-ago period. Its $1.53 billion in revenue also marked a 3% increase compared to last year. Health insurers — Health-care stocks jumped after The Wall Street Journal reported Monday that the Trump administration will increase payment rates for Medicare insurers to 5.06% next year, compared to the 2.23% increase proposed by the Biden administration. Shares of Humana , CVS Health and UnitedHealth climbed 15%, 9% and 8%, respectively. Lockheed Martin — The aerospace and defense stock added 2% after Vietnam said it would buy U.S. defense and security products in an attempt to narrow its trade gap. Broadcom — Shares popped 3% after the chipmaker announced a $10 billion share repurchase program authorization through year-end. The announcement "reflects the board's confidence in the strength of Broadcom's diversified semiconductor and infrastructure software product franchises," CEO Hock Tan said in a statement. Marvell — Shares advanced 4% in premarket trading after the company agreed to sell its auto ethernet business to Infineon Technologies for $2.5 billion in cash. The transaction is expected to close this year. Johnson & Johnson — The pharma stock climbed 2% following an upgrade at Goldman Sachs to buy from neutral. Analyst Asad Haider noted a "range of opportunities across therapeutic areas." Charles Schwab — The financial stock popped 2.7% on the back of Morgan Stanley's upgrade to overweight from equal weight. Morgan Stanley said it likes brokers with more defensive revenue sources and idiosyncratic drivers of earnings growth. Ross Stores , Ralph Lauren — Ross Stores and Ralph Lauren popped 2% and 4%, respectively, after Goldman Sachs upgraded the apparel stocks to overweight. The bank noted that Ross should perform better going forward against a slower macroeconomic backdrop. Meanwhile, Ralph Lauren possesses the global diversification and pricing power to limit downside risk induced by tariffs. Greenbrier — The stock slipped 2% after the railcar manufacturing company cut its revenue guidance for the full year. Greenbrier anticipates revenue to come in between $3.15 billion and $3.35 billion. It previously guided for revenue between $3.35 billion and $3.65 billion. Eli Lilly — Shares added 2% after Goldman Sachs assumed coverage of the pharmaceutical giant at a buy rating. Analyst Asad Haider noted a "compelling entry point" at the stock's current levels. Dave & Buster's Entertainment — Shares rose nearly 2% after management for the entertainment company issued positive comments on its business outlook. Interim CEO Kevin Sheehan said he expects "results in March and April have notably improved from the trend of Q4 and February, and we expect results to continue to improve in the coming months." Janover — Shares fell 17% in premarket trading after rallying more than 800% on Monday following the software company's announcement of a crypto treasury strategy that would be focused on the Solana token. The company also plans to change its name and ticker this year. — CNBC's Michelle Fox, Alex Harring, Fred Imbert, Tanaya Macheel and Sarah Min contributed reporting. Get Your Ticket to Pro LIVE Join us at the New York Stock Exchange! Uncertain markets? Gain an edge with CNBC Pro LIVE , an exclusive, inaugural event at the historic New York Stock Exchange. In today's dynamic financial landscape, access to expert insights is paramount. As a CNBC Pro subscriber, we invite you to join us for our first exclusive, in-person CNBC Pro LIVE event at the iconic NYSE on Thursday, June 12. Join interactive Pro clinics led by our Pros Carter Worth, Dan Niles and Dan Ives, with a special edition of Pro Talks with Tom Lee. You'll also get the opportunity to network with CNBC experts, talent and other Pro subscribers during an exciting cocktail hour on the legendary trading floor. Tickets are limited!