NVIDIA's Dark Fiber Buildout Sparks Rally in Taiwan's Optical Communications Stocks

The Scale and Technical Architecture of NVIDIA's Dark Fiber Acquisition

According to UDN's report on foreign media coverage, NVIDIA is reportedly planning to spend US$5 billion to US$10 billion acquiring long-haul "dark fiber" across the United States, aiming to build a self-owned high-speed fiber network as an AI "highway" and reduce reliance on traditional telecom carriers and hyperscale cloud providers (E4). UDN attributed the same US$5–10 billion, three-year figure to foreign outlets Gurufocus and WCCFtech (E15).

Research firm Wolfe Research, cited by UDN, said NVIDIA is buying up large volumes of long-haul dark fiber nationwide, with each route configured to carry up to 100 fiber pairs, which Wolfe Research said shows NVIDIA is "actively building its own AI network infrastructure" (E5).

Anue (鉅亨網/cnyes) reported a slightly different figure: NVIDIA is said to be spending approximately US$10 billion over the next three years to acquire US long-haul dark fiber and build a proprietary AI fiber backbone (E12). UDN also described NVIDIA as combining dark fiber purchases with DWDM (dense wavelength-division multiplexing) technology to build a cross-data-center autonomous AI backbone network — a report UDN said triggered a "strong rebound" in optical communications stocks, with Lianjun (聯鈞, 3450), Huanyu-KY (環宇-KY, 4991) and Xunxin-KY (訊芯-KY, 6451) leading the advance and hitting the daily limit-up together (E1).

Dark Fiber's Origins and Existing Idle Capacity

UDN traced the origin of "dark fiber" to the era of US telecom deregulation, when carriers over-built long-haul fiber networks. When the dot-com bubble burst in 2000, roughly 97.5% of the fiber that had been laid sat idle underground — cable that was physically installed but never connected to transmission equipment, i.e., never "lit." This unused, unlit fiber is what the industry calls dark fiber (E9). That historical overbuild is the pool of infrastructure UDN and Wolfe Research say NVIDIA is now moving to acquire.

NVIDIA's Strategic Rationale for High-Speed Transport Networks

According to UDN, NVIDIA CEO Jensen Huang (黃仁勳) has repeatedly emphasized that while compute matters, GPUs without high-speed transport are left simply waiting for data to arrive. UDN reported that NVIDIA's recent buildout has folded "transport technology" into its overall architecture — spanning intra-rack high-speed transport via NVLink and silicon photonics, as well as edge-computing AI RAN, and that NVIDIA has invested in Nokia (諾基亞) to accelerate AI RAN development (E8).

UDN further reported that by combining Neocloud infrastructure with a dark fiber network, NVIDIA could offer "GPU-as-a-Service" (GPUaaS) directly to small and mid-sized enterprises and startups. Historically NVIDIA has sold GPUs outright while competing against a crowded field of ASIC rivals; UDN said the Neocloud-plus-dark-fiber combination could let these customers draw on enterprise-grade GPU compute on demand without investing in and maintaining physical hardware (E11).

Which Optical Communications Supply Chain Players Stand to Benefit

UDN named several component makers as likely beneficiaries of the dark fiber buildout:

• Boruowei (波若威, 3163) — described by UDN as the "priority beneficiary," already an NVIDIA supply chain member with years of expertise in WDM (wavelength-division multiplexers), optical multiplexer/demultiplexer components, and fiber amplifier components, serving as a primary passive-component OEM/ODM partner for optical transmission module and equipment makers (E2).
• Lianjun (聯鈞) and Huanyu-KY (環宇-KY) — UDN noted optical communications cannot do without lasers; Lianjun, as a laser foundry, and Huanyu-KY, which is moving into CE Laser production, are both positioned to benefit (E3).
• Guangsheng (光聖, 6442) — UDN said Guangsheng focuses on high-density fiber patch panels and high-end optical connectors, and stands to directly benefit from hardware procurement tied to dark fiber's point-to-point physical wiring and splicing needs (E6).
• Huaxingguang (華星光, 4979) — UDN identified Huaxingguang as a representative supplier of high-speed optical transceiver modules and data-center-interconnect (DCI) modules, since dark fiber's role as a cross-data-center transmission path requires the high-power, long-reach/ZR 800G and 1.6T optical transceiver modules at each end for optical-electrical conversion (E7).

Dark Fiber Buildout's Ripple Effect on ODM and Financing Ecosystem

Beyond optical component makers, UDN reported that institutional investors expect NVIDIA's dark fiber buildout, combined with associated financing partnership models, to benefit major ODM assemblers — specifically Foxconn (鴻海, 2317), Quanta (廣達, 2382), and Wistron (緯創, 3231) (E10).

Stock Market Reaction Across Optical Communications Stocks

The rally played out across two separate trading sessions covered by different outlets. On 2026-07-21, UDN reported Lianjun (3450), Huanyu-KY (4991) and Xunxin-KY (6451) hit the daily limit-up together (E1). On 2026-07-23, Anue/cnyes reported Lianya (聯亞, 3081-TW) hit the limit-up for a second consecutive day (E12), while Huaxingguang (4979-TW), Lianjun (3450-TW) and Guanghuan (光環, 3234-TW) also briefly touched the limit-up, leading broader gains across optical communications names (E13). Anue/cnyes additionally reported Boruowei (3163-TW), Shangquan (上詮, 3363-TW), Guangsheng (6442-TW) and Zhongda-KY (眾達-KY, 4977-TW) rose more than half of a limit-up band (E14).

What This Means

The two funding figures reported two days apart — UDN's US$5–10 billion range (citing Gurufocus and WCCFtech) and Anue's roughly US$10 billion — sit at the same upper bound and cover the same three-year window, suggesting the reporting converged even as the exact figure remained unsettled. That spending is aimed at a resource pool UDN traced back to the 2000 dot-com bust, when about 97.5% of built US fiber went unused; the scale Wolfe Research described — up to 100 fiber pairs per route — indicates NVIDIA is drawing deeply on that decades-old overbuild rather than laying new cable. The market reaction also shows a widening circle: the first wave of limit-up moves on 2026-07-21 (Lianjun, Huanyu-KY, Xunxin-KY) was followed two days later by a second wave reported by Anue/cnyes that added Lianya, Huaxingguang, Guanghuan, Boruowei, Shangquan, Guangsheng and Zhongda-KY — with Lianjun appearing in both waves, first at full limit-up and then only briefly touching it on the second day. Beyond the pure-play optical component names, UDN's sourcing extends the beneficiary list to ODM assemblers Foxconn, Quanta and Wistron, indicating the dark fiber buildout is being read by institutional investors as a hardware-and-financing story that spans passive optical components, laser production, transceiver modules, and large-scale system assembly.