Check out the companies making headlines before the bell: CrowdStrike – The cybersecurity stock rose 3.4% after an upgrade to buy from hold at Deutsche Bank. Analyst Brad Zelnick said the market is “still not fully appreciating the extent to which AI will expand the market for cybersecurity.” Cybersecurity peer Palo Alto Networks gained 2% in sympathy. Rivian – The stock climbed 3.8% after the electric vehicle company was upgraded to buy at UBS . Analyst Joseph Spak said the stock’s recent sell-off presents a buying opportunity ahead of an inflection in its R2 midsize SUV ramp. Micron , SanDisk , Western Digital – Memory stocks rose broadly as traders appeared to be moving back into artificial intelligence names following a steep sell-off on Friday. Micron, Sandisk and Western Digital climbed around 2% each. Estée Lauder – Shares climbed 3.5% after the beauty company reported fiscal first-quarter results that beat analyst expectations. Estée Lauder earned an adjusted 72 cents per share on revenue of $3.72 billion. Analysts polled by FactSet expected a profit of 51 cents per share on revenue of $3.65 billion. The company also raised its full-year earnings outlook. Lumentum , Marvell Technology — Shares of Marvell ticked 3% higher, while Lumentum rose 2% before being halted, after the former agreed to acquire the latter company in an all-stock deal that values Lumentum at $115 billion . The transaction is expected to close in the first half of 2028. ExxonMobil , Chevron , Valero – Energy stocks took a dip as oil prices declined to start the week. ExxonMobil lost 1.2%, while Chevron slipped nearly 1%. Valero pulled back 1.5%. Bloom Energy , Vertiv — Both names rebounded slightly, as investors scooped them up following a pullback on Friday. Bloom Energy climbed 2.3% after plunging 8% in the previous session. Vertiv gained 2.5% higher after the digital infrastructure technology company slid 5% on Friday. — CNBC’s Fred Imbert contributed reporting