Fibre spot prices are four to six times last year's as AI data centres take the supply

01The line: three fibres, one year

The steepest rise is in G.657.A2, the ITU’s bending-loss insensitive fibre, which TrendForce says is used for cabling inside data centres.¹⁷ G.652.D, the ITU’s standard single-mode fibre and what TrendForce calls mainstream telecom fibre, rose next. G.654.E, the cut-off shifted fibre TrendForce calls AI backbone fibre, used between data centres and in high-capacity backbones, rose least, from the highest starting price.¹²

02What drives it

Demand. TrendForce names AI data centres, links between data centres and high-capacity backbones. Data centres take 18–20% of 2026 demand and, it projects, 30–35% in 2027; chipmakers and telecom operators are building related networks too. It says supply has been tight since late 2025.¹ Corning’s numbers point the same way. Corning’s Optical Communications sales rose 32% to US$2.07bn in the quarter to June, with Enterprise Networks up 65% and, in Corning’s words, “Gen AI product sales growing significantly faster”. The same release recorded a multiyear supply agreement with Amazon for its US data centres.⁵

Supply. Fibre plants ran at 92% of capacity in 2026, and makers’ stock fell from four months in 2024 to one. New capacity starts with the preform, the glass rod fibre is drawn from, and adding preform capacity takes 18–24 months, so plans made now arrive late.¹ In May, Corning and NVIDIA announced that Corning would expand its US fibre production capacity by more than 50%.⁶

Who says it is different this time. TrendForce argues this shortage differs from past telecom cycles because it comes from sustained new demand from AI data centres, not a one-off build.¹ Corning’s Mike O’Day, announcing the Verizon deal, said “Gen AI and broadband expansion are part of the same transformative opportunity”.⁴ Both are sellers’ or forecasters’ readings. We found no published forecast of an earlier end to the shortage, and none of a later one.

03What it means for a buyer

Carriers are buying years ahead. TrendForce says operators are moving from short-term purchases to long-term agreements.¹ Verizon’s, announced on 8 September, covers “80+ million miles” of fibre and connectivity from 2027 to 2032, for its broadband build and for long-haul links between AI data centres.⁴ The leased lines, internet links and dark fibre that branches and campuses rent run over carrier networks like this one.

Lead times, not only prices. With some makers booked into the first quarter of 2027 and new preform capacity 18 to 24 months away, a project that needs new fibre runs in 2027 is competing for supply already promised.¹ A campus or branch project buys installed cable, not bare fibre. We found no published figure for how much of a cabling quote the fibre is, so we cannot say how much of a four- to six-fold fibre price reaches a project budget. TrendForce does not price multimode fibre, which many in-building links use.²