Core Insights - Billionaire investor David Tepper of Appaloosa Management made significant portfolio adjustments in Q4, notably reducing stakes in AI chip stocks while increasing investments in companies heavily investing in AI infrastructure [1] Group 1: Portfolio Adjustments - Tepper reduced his position in Nvidia by over 10% and cut his stake in Advanced Micro Devices (AMD) by two-thirds, although Nvidia remains his seventh-largest position [2] - Despite reducing stakes in Nvidia and AMD, Tepper tripled his position in Micron Technology, which is benefiting from a supercycle in DRAM with high demand and short supply [4] - Tepper also increased his investment in Taiwan Semiconductor Manufacturing (TSM), which supports the manufacturing of GPUs and AI chips [4] Group 2: Investments in Hyperscalers - Tepper funneled some of the funds from reduced stakes in Nvidia and AMD into three large hyperscalers that are investing heavily in AI chips [5] - He increased his position in Alphabet by nearly 30%, making it his second-largest holding, as its cloud computing unit is rapidly growing and leveraging custom AI chips for cost advantages [6] - Tepper raised his stake in Meta Platforms by over 60%, making it his fifth-largest holding, as the company successfully integrates AI to drive growth and plans to continue aggressive investments in AI [7]