Why Ciena, Lumentum and other optical stocks were among the market’s biggest losers on Monday

Why Ciena, Lumentum and other optical stocks were among the market’s biggest losers on Monday Why Ciena, Lumentum and other optical stocks were among the market’s biggest losers on Monday The sharp moves could partly be a reaction to recent cautious commentary on AI spending Shares of Lumentum fell nearly 10% on Monday. /iStockphoto Artificial-intelligence stocks came under pressure Monday, with optical and networking stocks among the leading decliners. closed down 10%, 9.8% and 7.9%, respectively, while shares of Cisco Systems Copyright ©2026 MarketWatch, Inc. All Rights Reserved. 87990cbe856818d5eddac44c7b1cdeb8 Meta is back on the AI leaderboard with its new family of Wonder models Trump’s ‘energy ceasefire’ collides with real-world problems of dwindling fuel supplies These stocks could be the future winners —and losers — of a massive shift in IT spending The Points Guy on the best travel rewards cards for beginners ‘The house is worth $925,000’: My sister moved in with our mother, 78, and says she deserves the family home. Hannah Pedone is a New York–based technology reporter for MarketWatch.

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