Seagate and Western Digital Surge as AI Fuels 156% Spike

- Legacy tech hardware firms drive S&P 500 rally amid AI boom. - Analysts warn of overvaluation risks in cyclical markets. On September 21, 2025, Cryptopolitan reported that legacy tech firms like Seagate Technology, Western Digital, and Micron Technology are spearheading the S&P 500’s 2025 rally. This growth is driven by surging demand for artificial intelligence infrastructure. The stock performance of these companies has been exceptional. Seagate is up 156%, Western Digital has gained 137%, and Micron has jumped 93% year to date. These gains stem from the billions of dollars that Big Tech firms, including Microsoft and Alphabet, are investing to expand AI capabilities through data centers and advanced chips. These legacy firms manufacture foundational products such as hard drives and memory chips, which are critical for operating large-scale AI systems like language models and other machine-learning applications. Massive investments in AI infrastructure from established industry leaders initially propelled growth for graphics chipmakers like Nvidia and semiconductor firms such as TSMC. Now, traditional hardware manufacturers are the latest players to benefit from this trend, and their revenue projections reflect strong momentum. According to the report, analysts expect Micron to achieve 48% revenue growth this year. They project Seagate will grow by 39% in fiscal 2025, and Western Digital anticipates a recovery in its sales figures. Despite this optimism, market analysts have raised concerns about the possibility of overvaluation. Seagate, Western Digital, and Micron are trading below the S&P 500's average forward earnings multiple of 23x. However, their current valuations exceed many analysts' price targets. For example, Seagate’s stock is trading at 20 times expected earnings. Some experts argue that the hardware business remains cyclical and warn that the best investment opportunities in this sector may have already passed. Beyond the three key names, other firms within the AI infrastructure ecosystem are also experiencing notable stock gains. These companies include Broadcom, SanDisk, Oracle, and Vistra. The report highlights that these increases reflect the broader impact of AI-driven demand across multiple layers of the supply chain.