India, Aug. 2 -- Apple shares fell nearly 10% on Friday after a disappointing forecast showed that the iPhone maker was struggling to secure enough components as the AI-driven data center boom strains global supply chains. The drop, if sustained, would mark the stock's worst day since the pandemic-driven selloff in March 2020. It would erase nearly $500 billion from Apple's market capitalization and return the crown of the world's most valuable company to AI chip giant Nvidia, days after reclaiming it.

Tim Cook, widely hailed as a supply-chain genius, called the shortages "very significant" and said Apple had limited options to address them, speaking on his final earnings call as CEO before handing the reins to John Ternus in September a...