Amkor's AI Tailwind Is Real, but the Valuation Is Getting Rich

Amkor Technology (AMKR) has been one of the stronger performers in the semiconductor supply chain this year, and the reason is straightforward: the AI chip boom runs through its factories. The outsourced chip-packaging specialist reported fourth-quarter revenue of $1.74 billion, up 17% from a year earlier and ahead of the $1.69 billion consensus. Adjusted earnings of $0.58 a share beat the $0.51 estimate. The headline number was advanced packaging revenue, which rose 35% year over year. That segment covers the high-end chip-stacking and interconnect work that powers Nvidia's and AMD's AI accelerators, along with custom designs from cloud hyperscalers.

Amkor's business model is outsourced semiconductor assembly and test, or OSAT. It takes finished wafers from foundries like TSMC and turns them into finished chips – cutting, stacking, bonding, and testing. The AI boom has been a direct tailwind because the most advanced AI chips require packaging technologies like 2.5D and 3D stacking that Amkor specializes in. Those processes are more complex and more expensive than standard packaging, which lifts revenue per wafer and margins.

Management guided for first-quarter revenue of $1.45 billion to $1.55 billion, with the midpoint of $1.5 billion roughly in line with the $1.49 billion consensus. The company also said it expects capital expenditures of $750 million to $850 million for 2026, up from $700 million in 2025, as it expands capacity for advanced packaging in Vietnam and at its new facility in Arizona.

That Arizona plant is a key piece of the story. Amkor is building a $2 billion facility in Peoria, a suburb of Phoenix, with backing from the CHIPS Act. The site is designed to serve the same ecosystem of chip designers and foundries that have clustered in the region, including TSMC's nearby fab. The plant is expected to begin production in 2027 and will focus on advanced packaging for AI and high-performance computing. The location gives Amkor a domestic production base for a supply chain that has been almost entirely Asia-based, which matters for customers who want geographic diversification.

The stock trades at about 22 times forward earnings, a premium to the broader semiconductor sector but not out of line for a company with double-digit revenue growth and expanding margins. The risk is that the AI capex cycle slows, or that competitors like ASE Technology and JCET add enough advanced packaging capacity to compress pricing. For now, the order books are full, and the guidance suggests the trend has legs.

The next catalyst is the first-quarter earnings report, expected in late April. The market will be watching for updates on the Arizona timeline and for any signs that the AI packaging backlog is still growing.