TLDRAppaloosa Management under David Tepper expanded positions in five major AI-related stocks during the fourth quarterMicron’s stake was tripled to 1.5 million shares amid reports that memory chips are completely sold out through year-endAlphabet crossed the $400 billion annual revenue milestone with Google Cloud revenue surging 48% year-over-yearDespite beating Q4 estimates with $59.89B revenue, Meta stock faces pressure from its massive $115–$135B AI infrastructure investment forecastMicrosoft shares have declined more than 25% from peak levels, now trading at notably compressed valuation multiplesHedge fund manager and billionaire David Tepper submitted his 13F filing for the fourth quarter on February 17, revealing portfolio adjustments at Appaloosa Management. With a concentrated portfolio of only 45 equities, Tepper adjusted five positions within his top 10 holdings during the period.Appaloosa expanded its Alphabet holdings by 28.7%, purchasing an additional 399,431 shares to bring the position to approximately 8.1% of total assets under management. The tech giant crossed $400 billion in annual revenue for the first time in its history, powered by Google Cloud’s impressive 48% year-over-year expansion to $17.7 billion. Alphabet recently claimed the title of America’s most profitable corporation, surpassing both Apple and Microsoft.Alphabet Inc., GOOGLThe most dramatic portfolio adjustment involved Micron Technology. Tepper expanded his position threefold, jumping from 500,000 shares to 1.5 million. This move comes as the semiconductor manufacturer reports its memory chip inventory is fully allocated through the remainder of the year, driven by explosive AI data center requirements. Micron delivered Q4 revenue of $13.64 billion alongside earnings per share of $4.78, exceeding analyst projections.Micron and Meta: Two Very Different BetsMicron stock has skyrocketed 348% over the past twelve months and continues its ascent with a 35% gain year-to-date. The semiconductor company is committing $200 billion toward manufacturing expansion, including two Idaho fabrication facilities totaling $50 billion and a massive $100 billion New York manufacturing complex.Tepper increased his Meta holdings by 62% during the fourth quarter, though this investment has underperformed expectations. The social media giant posted Q4 revenue of $59.89 billion with earnings per share of $8.88, topping consensus forecasts. Nevertheless, shares tumbled following Q3 results as investors digested the company’s aggressive capital expenditure plans.Meta has outlined plans to invest between $115 billion and $135 billion in AI infrastructure throughout 2026. Advertising revenue accounted for $58.1 billion of Q4’s total. Shares remain below their previous peak and have yet to stage a meaningful recovery.Taiwan Semiconductor Manufacturing Company represents another Q4 addition to Appaloosa’s portfolio. The foundry produces the majority of advanced logic semiconductors powering AI systems, positioning it as a primary beneficiary of infrastructure buildouts by hyperscale technology companies.Microsoft Trades at Historically Low ValuationMicrosoft received a modest 8% position increase from Tepper during the fourth quarter. The software giant’s shares declined substantially following its most recent quarterly report and currently sit more than 25% below all-time highs. The stock’s price-to-earnings multiple has compressed to levels not observed in an extended period.Appaloosa’s subsequent 13F disclosure, covering the first quarter of 2026, is expected around mid-May. That report will reveal whether Tepper has added to his Microsoft position during the current market pullback.Alphabet shares are currently changing hands near $307. Micron is trading around the $415 level. Meta stock sits at approximately $655.The post David Tepper’s Appaloosa Management Doubles Down on AI: Five Major Tech Stock Purchases Revealed appeared first on Blockonomi.