Mostly, you pick a stock and expect to hold it for a few quarters, but sometimes you come across a business that makes you think very differently. With such businesses, every new earnings update strengthens your conviction instead of testing it. Celestica (TSX: CLS) feels like one of those rare stocks to me right now. The company is no longer just riding a short-term cycle, but it seems plugged directly into one of the biggest technology shifts investors have seen in decades.

As artificial intelligence (AI) is moving fast from just a buzzword to real-world deployment, the infrastructure behind it is becoming just as valuable as the software itself. What makes this story even more interesting is that the AI buildout still looks early. Spending plans of global tech giants are consistently expanding, capacity is being added, and customers are thinking in multi-year terms now. With the help of real fundamental factors, let me explain why Celestica stock is one I have no intention of selling.

AI infrastructure is the real driver here

If you don’t know it already, as a global provider of design, engineering, manufacturing, and supply chain solutions, Celestica has a growing focus on data centre infrastructure and advanced networking hardware. With the scaling capabilities of AI workloads, the demand for servers, switching platforms, and high-performance systems is surging, and this company is directly involved in building that backbone.

Celestica stock reflects this momentum clearly. Over the last year, the stock has surged 243% to currently trade at $467.12 per share, giving the company a market capitalization of roughly $53.7 billion.

Strong execution is showing up in the numbers

Interestingly, that AI-driven demand is clearly visible in Celestica’s recent financial results. In the fourth quarter of fiscal 2025, the company’s revenue jumped 44% YoY (year-over-year) to US$3.7 billion. This performance exceeded the high end of its guidance range, driven largely by strength in AI-related programs.

On the profitability side, Celestica’s adjusted operating margin rose to 7.7% in the latest quarter, up from 6.8%, as higher volumes and better operating leverage kicked in. As a result, its adjusted earnings reached US$1.89 per share, compared to just US$1.11 a year ago.

For 2025, Celestica delivered a solid 28% YoY increase in its revenue, while its adjusted earnings also climbed 56% YoY to US$6.05 per share. These gains were largely driven by strong execution in its connectivity and cloud solutions segment, which continues to benefit from accelerating AI infrastructure investments.

Multi-year AI visibility changes the picture

The most interesting part of Celestica’s growth story is what lies ahead. Recently, the company raised its 2026 outlook, now expecting US$17 billion in revenue and US$8.75 per share in adjusted earnings. This increase is tied to stronger demand visibility and alignment with customers who are planning capacity years in advance.

Meanwhile, Celestica is also backing that confidence with action. Its planned capital spending for 2026 has been increased to US$1 billion, fully funded through operating cash flow. These investments include the company’s expanded U.S. manufacturing to support Google Tensor Processing Unit (TPU) systems, additional capacity in Southeast Asia, and new design centers to support next-generation networking platforms.

These solid fundamentals clearly back the idea that AI infrastructure spending is still in its early phase, with a long runway ahead. For me, that is the one clear reason I’m not selling Celestica stock.