A stock that gained over 400% in a single year just lost nearly 40% of its value in four trading days. Fujikura Ltd., the Japanese optical fiber cable manufacturer that became one of the most celebrated plays on AI infrastructure demand, delivered an earnings forecast so far below expectations that it triggered a selloff felt well beyond Tokyo.
The company’s operating-profit target for fiscal 2028, the year beginning April 2028, came in at ¥315 billion, roughly $2 billion. Analysts had been expecting ¥455 billion. That’s a ¥140 billion gap between what management sees and what the market had priced in. In English: the company thinks it will make about 30% less money than investors were betting on.
The anatomy of a four-day wipeout
On May 19, Fujikura shares dropped as much as 17% in a single session. That was just the opening act. Over the following three trading days, selling continued, bringing cumulative losses to approximately 40% and erasing roughly ¥5.6 trillion in market capitalization.
To put that in perspective, Fujikura had been one of the best-performing stocks in the Nikkei 225. The company rode the AI infrastructure wave to gains exceeding 400% in 2024. Through late October 2025, shares had tacked on another 160%. For a cable company, that’s the kind of performance usually reserved for the firms actually building the AI models, not the ones making the wires that connect the servers.
The company manufactures optical fiber cables and high-speed interconnects that are essential for data centers processing AI workloads. Every new hyperscale facility that Nvidia, Microsoft, or Google announces needs enormous quantities of advanced cabling. Fujikura was, in the minds of many investors, a picks-and-shovels play on the gold rush.
Why the gap matters beyond one stock
The ripple effects were visible almost immediately. Broader losses appeared across Japanese tech and AI-linked stocks in the sessions following Fujikura’s announcement, particularly ahead of major earnings reports from companies like Nvidia.
What this means for investors
A 40% decline in four days for a company with legitimate products and real revenue is not normal price discovery. It’s a repricing of risk that had been systematically ignored during the euphoric phase. Investors who bought Fujikura at its highs weren’t wrong about the company’s products being essential. They were wrong about how much of the upside was already baked into the price.