Shares of Corning Incorporated experienced a notable decline in trading on Thursday, March 5, 2026, shedding roughly 4.4% to trade around $138.43 by late morning. The selloff was precipitated by commentary from Broadcom Chief Executive Hock Tan, who tempered near-term expectations for the adoption of optical connectivity within artificial intelligence infrastructure.
Copper's Persistent Role in AI Scale-Up
During Broadcom's earnings discussion, Tan informed analysts that customers currently prefer direct-attached copper cabling for "scale-up" connections inside AI server racks. These are the critical, short-run links that wire accelerators together within a single enclosure, where power efficiency and latency are paramount. "CPOs will come in its time. Not this year, maybe not next year," Tan stated, referring to co-packaged optics technology. In a contrasting move, Broadcom's stock gained 5.3% on the session.
The remarks underscore a significant timing challenge for companies like Corning, which have become popular investments for those betting on AI-driven data center expansion. The prevailing investment thesis has been straightforward: escalating AI workloads demand faster data transfer, eventually hitting the limits of copper's power efficiency and thus necessitating a broad shift to fiber-optic solutions.
Corning's Revised Timeline and Strategy
Corning's own leadership had recently adjusted expectations. Speaking at a Morgan Stanley event earlier in the week, Chief Financial Officer Ed Schlesinger acknowledged that the "scale-up" process for AI networking would take longer than some had hoped. "I don't think we're gonna see scale up ... for a couple years," Schlesinger said, pointing to a more substantial inflection point closer to 2028. However, he noted that "scale-out" demand—which forms the backbone linking racks across the data hall—continues to build momentum.
Despite the near-term headwind, Corning has been actively securing its long-term position. The company is collaborating with Broadcom on co-packaged optics solutions slated for 2025, where Corning would supply optical components for Broadcom's Bailly CPO system. This technology aims to place optical links directly onto the chip package, targeting higher density and lower power consumption in large AI clusters. Furthermore, Corning locked in a major multi-year supply agreement with Meta Platforms in January, a deal valued up to $6 billion for fiber-optic cables and related equipment for Meta's AI data centers.
Market Reaction and Analyst Perspective
The market's reaction was pronounced and not limited to Corning. Ciena, another key player in optical networking, saw its shares tumble approximately 15.2% on the day. The selloff highlights the sensitivity of these stocks to the anticipated adoption curve of next-generation data center technologies.
Analysts viewed the comments as aligning with an emerging trend of gradual adoption. William Blair analyst Sebastien Naji noted, "CPO adoption is still likely 2-3 years away from seeing a meaningful inflection." This represents a delay of at least two years from some prior market expectations. The central conflict has become one of timing: while copper's resilience may outlast optimistic forecasts, the fundamental need for optical solutions in the long run remains unchallenged, particularly for the power-hungry scale-up segment within racks.
Balancing Near-Term Reality with Long-Term Vision
Corning now sits at a strategic crossroads. Demand for fiber between racks (scale-out) is undeniably climbing, but penetrating the interior of the rack (scale-up) appears to be on a slower trajectory. The company's revised Springboard plan, which now targets about $24 billion in revenue by 2028, must account for this pacing. The risk for Corning and its investors is that if hyperscale data center operators continue utilizing copper within racks for an extended period or moderate spending on new AI clusters, the optical growth surge may materialize later and less predictably than currently modeled.
Thursday's trading action made it clear which narrative the market is prioritizing in the short term. While the long-term opportunity in AI infrastructure remains vast, investor patience is being tested as the industry grapples with the practical and economic realities of integrating advanced photonics. The journey to co-packaged optics continues, but the path has grown longer, prompting a recalibration of expectations across the sector.
