Fujikura Ltd. shares plunged as much as 17% after the Japanese optical-fiber maker gave investors a three-year outlook that crushed hopes the AI boom would turbocharge demand for high-density network cables. The sell-off reflected growing skepticism that capex spending by hyperscalers will sustain the kind of revenue growth wire manufacturers counted on.

The company targets operating income of ¥315 billion ($2 billion) in the fiscal year starting April 2028, trailing the average analyst estimate of ¥455 billion by roughly ¥140 billion. That gap between management's view and Wall Street's numbers triggered the steepest single-day decline in Fujikura's valuation since the AI hype cycle began accelerating.

Investors had priced in a rosier scenario where every major cloud provider would need to upgrade its data-center interconnects simultaneously. Fujikura's conservative forecast suggests that build-out timelines may stretch or that competition from other cable makers is keeping pricing pressure high. Bloomberg Markets coverage of the reaction pushed trading volume sharply higher as retail and institutional holders reassessed exposure.

The ¥140 billion shortfall between forecast and consensus effectively punctures the assumption that AI infrastructure spending runs on a straight line. For suppliers like Fujikura, demand still exists—but the market is demanding proof that it will sustain current multiples.