David Tepper Tripled Micron, Exited Every Airline, and Bet on AI Power

Appaloosa Management filed its Q1 2026 13F on May 15, 2026. David Tepper had tripled the Micron Technology position from 500,000 shares to 1.5 million, fully exited American, Delta, and United, doubled Vistra Energy, and slashed Microsoft by roughly 82%. The portfolio, $5.93B across 31 holdings, is now top-heavy in semiconductors, hyperscalers, and electric utilities. Yahoo Finance summarized the filing as “AI all-in.” The Micron triple is the anchor stat.

Key facts at a glance

• Micron Technology position tripled, from 500K shares to 1.5M shares, per the Q1 2026 13F on SEC EDGAR.
• American Airlines, Delta Air Lines, and United Airlines were exited completely.
• Vistra Energy doubled. SanDisk position initiated.
• Uber moved from the number-17 holding to the number-four.
• Microsoft was cut by approximately 82%. Alibaba was trimmed by approximately 33%.
• Portfolio total: $5.93B across 31 holdings. Top five: Amazon (15%), Micron (9.5%), Alphabet (8.4%), Uber (7.7%), Taiwan Semiconductor (7.6%), per Yahoo Finance coverage.

Who is David Tepper

David Tepper founded Appaloosa Management in 1993. The fund’s public profile is built on a small number of well-timed macro calls, including distressed bank debt in 2009 and a China call in 2023. Tepper is not a high-frequency trader. When Appaloosa moves a position by 200% in a single quarter, the move is the message.

The fund’s recent 13Fs have already tilted toward US technology and hyperscaler-adjacent names. The Q1 2026 filing extends that tilt further, with concentrated bets on memory chips, power generation for data centers, and ride-hailing infrastructure that ties to autonomous-vehicle compute demand.

What the 13F actually shows

The Q1 2026 filing has three readable threads: a deep semiconductor build, an aggressive sector rotation out of airlines, and a power-generation overlay that fits the AI-infrastructure narrative.

The full-airline exit is the most visible single move. Tepper had been a public proponent of the airline sector in earlier cycles, and exiting all three majors in one quarter while loading into memory and utilities is a strong statement of where his attention is now allocated.

Why this matters

Three reasons the filing is being read carefully.

First, Micron at +200% in one quarter is uncommon for a position that was already on the book. Hedge funds usually scale into larger positions gradually. A triple in 90 days is a conviction call on memory pricing, the AI training and inference build-out, or both.

Second, the airline exits read as a complete macro thesis change, not a valuation trim. Appaloosa exited American, Delta, and United at the same time. The all-three-at-once shape of the move suggests the exit is sector-driven, not name-driven.

Third, Vistra Energy and the AT&T-style power-grid overlay (referenced in BBAE’s 13F summary) tie back to the same AI thesis. Modern data centers need enormous, reliable baseload power. A doubled Vistra position alongside the Micron triple is a coherent bet that the bottleneck for AI scaling is power and memory, not just compute.

What this 13F does not tell you

A 13F never tells the whole story, and an Appaloosa 13F has specific gaps worth naming.

• No timing. The airline exits could have happened in January or March. The pricing context for each exit is not visible in the filing.
• No short or derivative book. Appaloosa’s options book, including any hedges on Micron itself, does not appear here.
• No credit positions. Appaloosa is historically a credit-savvy fund. Distressed debt, sovereign positions, and structured credit do not appear on a 13F at all.
• No statement of conviction size. A 9.5% portfolio weight on Micron is large, but Appaloosa has held larger single-name concentrations historically. Whether 9.5% is the ceiling for this conviction is unknown.
• No commentary. Tepper is famously selective with public commentary. The next CNBC appearance or letter is where reasoning will live, not the 13F.

Reading the AI-infrastructure thread across the filing

The cleanest reading is that Appaloosa is sizing its AI exposure in the layers that have less hyperscaler-platform competition: memory, power, and mobility infrastructure. The Microsoft cut, in that frame, is profit-taking, not a rejection.

FAQ

How big is the Micron position now?

About 1.5 million shares, equal to roughly 9.5% of the $5.93B portfolio at quarter-end. Micron sits as the number-two holding behind Amazon.

Why did Tepper exit all three US airlines?

The 13F does not say. The fact that all three were exited together suggests a sector-level decision rather than three independent name-by-name calls.

Is this an AI bet?

The press shorthand is “AI all-in,” and the position mix supports that framing. Memory chips, hyperscaler equities, power generation, and autonomous-mobility infrastructure all tie to AI scaling. Appaloosa itself has not used the label publicly.

Did Appaloosa exit Microsoft?

No. Microsoft was cut by approximately 82% but a residual position remained. The press coverage at Yahoo Finance framed this as profit-taking, not a thesis change.

What is the largest Appaloosa position now?

Amazon, at about 15% of the book.