Mega-Cap Concentration Hits Record; David Tepper Doubles Amazon, Exits Airlines

First-quarter 13F filings reveal a dramatic repositioning by some of Wall Street's most influential money managers, with David Tepper's Appaloosa Capital exemplifying the trend. Tepper nearly doubled his Amazon stake, making it Appaloosa's largest disclosed equity holding at quarter-end, while simultaneously exiting every major US airline position. This move signals confidence that AI infrastructure and e-commerce logistics will outperform traditional sectors in an uncertain macro environment.

The broader pattern extends beyond Tepper. Seth Klarman's Baupost boosted its Amazon position by 47 percent, making it their top holding. Bill Ackman initiated a major position in Microsoft, citing the company's flexibility to remain competitive in the AI arms race. Berkshire Hathaway, under new CEO Greg Abel's leadership, boosted its Alphabet stake while exiting Amazon entirely, and returned to airlines with a $2.6 billion DeltaHow much an option's price changes per $1 move in the underlying. position. Trump's personal holdings, disclosed via ethics filings, show purchases of Meta, Oracle, Broadcom, and other tech names worth millions.

This concentration in mega-cap tech creates both opportunities and risks. The thesis appears to be that AI capex will sustain valuations despite elevated interest rates, and that platform ecosystems (Amazon, Microsoft, Google) will win out over pure-play hardware suppliers. However, the positioning also raises crowding risk; if even a modest fraction of these positions face redemptions or margin pressures, liquidity could evaporate quickly. Some analysts flagged that this is reminiscent of late-1999 dot-com positioning, though AI's economic fundamentals appear more durable.

The exit from airlines and traditional energy reflects skepticism about mean reversion in cyclical sectors. Berkshire's return to DeltaHow much an option's price changes per $1 move in the underlying. bucks this trend, though at significantly lower prices than peak airline valuations. Energy stocks have benefited from Iran war premium, yet mega-cap allocators are choosing to stay in tech rather than diversify. This suggests that portfolio managers believe AI and e-commerce tailwinds will outweigh energy upside even if oil remains elevated. The concentration metric now reaches levels unseen since the pre-2000 bubble, raising systemic concerns among risk managers.