Today, the optical fiber sector remains red-hot, with the entire sector hitting the daily limit again. However, I've noticed that many companies in the optical fiber sector are just riding on thematic hype, and quite a few have earnings bombs. Everyone must be careful not to step on a landmine. I've just sorted through it: among these surging stocks, five have annual reports that are earnings bombs, but there are also four with significant profit growth. Everyone must be cautious and not get the direction wrong.

First: JPT Optoelectronics $JPT Optoelectronics(SH688025)$ In 2025, the company's net profit grew by 98% to 133%, reaching 262 million to 309 million yuan. Deducted non-recurring profit grew by 140% to 184%, reaching 253 million to 300 million yuan. JPT's strong performance is mainly due to its position as a domestic leader in MOPA pulsed fiber lasers, with core products seeing sustained demand in areas like new energy power battery welding and tab cutting, deeply tied to top clients like CATL and BYD. At the same time, orders for consumer electronics MR inspection and photovoltaic TOPCon laser doping equipment are growing rapidly. The optical communication device business benefits from the explosion in AI computing power and data center demand, with products like MPO and FAU passing certification and entering top supply chains, achieving high growth. Combined with product structure optimization and scale effects improving gross margins, multiple factors are driving significant revenue and net profit growth.

Second: Yongding Co., Ltd. $Yongding Co., Ltd.(SH600105)$ In 2025, this stock's net profit grew by 226% to 388%, reaching 200 million to 300 million yuan. Yongding's strong performance is partly due to large investment gains from the disposal of equity in a joint venture's real estate project, boosting current period profits. On the other hand, the core optical communication business benefits from AI computing power and a simultaneous rise in fiber optic cable volume and price, with optical modules and high-end fiber optic product orders and gross margins improving together. Additionally, the high-temperature superconducting business is gradually materializing, and the automotive wiring harness business is recovering, leading to a significant increase in main business profitability, collectively driving notable performance growth.

Third: Changxin Bochuang $Changxin Bochuang(SZ300548)$ In 2025, this stock's net profit surged by 344% to 413%, reaching 320 million to 370 million yuan. Changxin Bochuang's strong performance is driven by the explosion in AI computing power demand, leading to a simultaneous rise in data communication business volume and price, and an increased share of high-margin products. Combined with the high growth of its controlled subsidiary Changxinsheng and an increased ownership stake boosting consolidated profits, these factors collectively drove net profit growth of over three times year-on-year.

Fourth: LUSTER LightTech In 2025, the company's revenue grew by 30% to 2.9 billion yuan, and profit grew by 51% to 161 million yuan. LUSTER LightTech's strong performance is mainly due to the rapid scaling of its core AI + machine vision business in areas like consumer electronics, display semiconductors, and new energy lithium battery inspection, with product structure optimization improving gross margins. At the same time, the acquisition of industrial camera brand JAI was completed, overseas business and high-end client expansion went smoothly, and synergies emerged. Combined with the company's strategic focus and contraction of non-core businesses, overall operational efficiency improved, collectively driving significant revenue and net profit growth.

Optical fiber leaders with earnings bombs in 2025:

First: Hangzhou Cable Co., Ltd. In 2025, the company suffered a loss of 300 million yuan, with profit declining by 318%. Hangzhou Cable's sharp performance decline and loss in 2025 are primarily due to a triple whammy: a one-time large asset impairment, a continuous decline in main business gross margins, and the drag from new business investment periods. The company recorded a 264 million yuan fixed asset impairment provision for its wholly-owned second-tier subsidiary Hangzhou Yongte Information Technology Co., Ltd., directly eating up the full-year profit, which is the main cause of the loss. At the same time, core businesses like wire and cable were hit by significant price increases in major raw materials like copper and aluminum, coupled with intensified industry competition, leading to a nearly 10 percentage point drop in gross margins in the first three quarters, severely deteriorating profitability. Additionally, new businesses like new energy copper foil and optical communication are still in the capacity ramp-up and market development phase, not only failing to contribute profits but also generating high depreciation, R&D, and marketing expenses, further dragging down overall performance, ultimately leading to an estimated full-year loss of about 300 million yuan.

Second: Tongding Interconnection In 2025, this stock's net profit declined by 203% to 242%, with a net loss of 80 million to 110 million yuan. Tongding Interconnection's sharp performance decline and loss are mainly due to large impairment provisions on equity assets held, combined with fierce competition in the core communication cable business and rising raw material costs, leading to severe profitability deterioration and ultimately a loss.

Third: Yonggui Electric In 2025, this stock's net profit declined by 40% to 55%, falling to 57 million to 75 million yuan. Yonggui Electric's sharp performance decline is mainly due to the new energy vehicle business being hit by customer price pressure and increased depreciation from new production lines, causing a significant drop in gross margins. Additionally, interest expenses from convertible bonds sharply increased financial costs, while overseas business expansion is in the investment phase, with multiple factors collectively dragging down profitability.

Fourth: Robotechnik In 2025, net profit plummeted by 217%, with a net loss 60 million to 90 million yuan. Robotechnik's sharp performance decline is mainly due to weak downstream demand overcapacity in the photovoltaic industry, leading to a significant drop in revenue and gross margins from the photovoltaic equipment business. At the same time, after acquiring ficonTEC, R&D and operating expenses increased, equipment delivery cycles lengthened, and new businesses have yet to achieve scale profitability, with multiple factors collectively causing a sharp performance decline and loss.

Fifth: Zhicheng Technology In 2025, this stock's net profit plummeted by 1689%, with a net loss of 300 million to 450 million yuan. Zhicheng Technology's sharp performance decline is mainly due to the high-purity process system and wet process equipment business being hit by intensified industry competition and delivery falling short of expectations, leading to revenue decline. At the same time, R&D investment in high-end equipment continued to increase, pushing up expenses. Combined with a large one-time credit impairment provision and a significant reduction in non-recurring gains, multiple factors collectively caused a notable performance decline and loss.