Executive Summary / Key Takeaways

• ADTRAN Holdings is experiencing a robust resurgence, marked by five consecutive quarters of sequential revenue growth and four of year-over-year improvement, fueled by global fiber expansion, strategic vendor consolidation, and the increasing demand for AI-driven network upgrades.
• The company's differentiated portfolio, encompassing its SDX fiber access platforms, 800 Gig optical transport solutions, and AI-powered Mosaic One software, is driving significant market share gains, particularly in Europe, and delivering tangible operational benefits such as up to a 75% reduction in network-related trouble tickets.
• Disciplined operational execution, including the completion of its Business Efficiency Program and a strengthened capital structure through a recent convertible notes offering, has significantly improved profitability and cash flow, with non-GAAP gross margin reaching 42.1% in Q3 2025.
• Management projects continued operating margin expansion and earnings growth into 2026, targeting double-digit operating margins at approximately $315 million in revenue on a constant currency basis, supported by an anticipated improved BEAD spending environment and strategic cross-selling initiatives.
• Key considerations for investors include the ongoing DPLTA appraisal proceedings, the imperative to fully remediate internal control weaknesses, and the dynamic nature of global trade policies, which ADTRAN is actively addressing through supply chain diversification and hedging strategies.

Setting the Scene: ADTRAN's Core and Market Dynamics

ADTRAN Holdings, Inc. stands as a global provider of networking and communications platforms, software, systems, and services, with a core focus on the broadband access market. The company serves a diverse international customer base, including large, medium, and small service providers, utilities, municipalities, fiber overbuilders, cable/MSOs, small and mid-sized businesses (SMBs), and government agencies. Its overarching strategy centers on increasing unit volume and market share through the introduction of new products and succeeding generations of products that offer optimal selling prices and enhanced functionality.

The industry landscape in which ADTRAN operates is currently undergoing significant transformation. Key drivers include the relentless global demand for fiber expansion, the ongoing densification of 5G networks, the burgeoning investment in AI and cloud computing infrastructure, and a notable trend of vendor consolidation, particularly a shift away from high-risk vendors. ADTRAN's foundational strengths lie in its global presence, diversified customer base, and operational flexibility, including manufacturing capabilities across the U.S. and Europe, which position it to capitalize on these trends.

Competitive dynamics are intense, yet ADTRAN is actively gaining ground. The company is recognized as a "number one winner" in a significant market share disruption occurring in Europe, where a large incumbent player is being displaced. This momentum is expected to build over the next two to three years, further impacting ADTRAN's market position.

Technological Edge: Powering Next-Gen Networks

ADTRAN's competitive advantage is deeply rooted in its differentiated technology portfolio, spanning fiber access, optical networking, and subscriber solutions, all unified by its Mosaic software suite. The company's fiber access platforms, notably the SDX portfolio, are central to its offerings. The SDX 6330 platform alone has been instrumental in passing over 10 million homes with fiber. Demonstrating continuous innovation, ADTRAN, in collaboration with Netomnia, deployed the UK's first commercial 50 Gig PON service using its new SDX 6400 Series in May 2025. These platforms are recognized for their high density, power efficiency, and software-based, disaggregated architecture, offering scalability for both small and large deployments.

In optical networking, ADTRAN provides solutions for securely interconnecting metro and regional networks over fiber. This includes open optical terminals, open line systems (OLS), optical subsystems, modules, and automation platforms. The company's M-Flex solution represents an industry-leading 800 Gig transport technology. Furthermore, its 100ZR+ and 400ZRE coherent pluggables have been validated for multi-vendor interoperability at the OIF Plugfest, underscoring their advanced capabilities. These optical solutions are crucial for supporting the increasing bandwidth, latency, and reliability requirements driven by distributed computing, edge processing, AI, and cloud computing.

For subscriber solutions, ADTRAN offers residential gateways, ONTs, Ethernet switching, and network edge virtualization. The company is at the forefront of Wi-Fi technology, with high demand for its Wi-Fi 7 platforms and offerings for multi-Gig Wi-Fi in residential and 100 Gig services for business applications. The SDG 9000 series was launched to address the specific needs of SMBs, MDUs, and community Wi-Fi.

A critical differentiator is ADTRAN's Mosaic software suite, which integrates and automates its entire networking portfolio from the optical core to the customer premise. The Mosaic One platform, including its Intellifi in-home Wi-Fi management solution, simplifies provisioning and monitoring. A recent innovation, Mosaic One Clarity, an AI-based application built on ADTRAN's carrier-grade Agentic AI platform, is designed for predictive maintenance, guided issue resolution, and proactive network optimization. Early customer trials of Mosaic One Clarity have shown promising results, demonstrating a reduction of up to 75% in network-related trouble tickets. This AI-driven approach to network intelligence is a clear example of how ADTRAN's innovation helps operators improve performance and efficiency, contributing significantly to its competitive moat and long-term growth strategy.

A History of Strategic Evolution and Operational Discipline

ADTRAN's current market position is a culmination of strategic evolution and a concerted effort towards operational discipline. A pivotal moment was the merger of ADTRAN, Inc. into ADTRAN Holdings, Inc. on July 8, 2022, followed by the Domination and Profit and Loss Transfer Agreement (DPLTA) with Adtran Networks SE, effective January 16, 2023. This strategic combination aimed to integrate technology portfolios and better address customer needs for high-speed connectivity from the network core to the end consumer.

In response to challenging market conditions in 2024, which saw revenue declines due to softer end markets, customer inventory reductions, and elevated interest rates, ADTRAN implemented a comprehensive Business Efficiency Program on November 6, 2023. This program involved salary reductions, an early retirement initiative, site consolidation plans (including the planned sale of its Huntsville headquarters), inventory write-downs from product discontinuances, and the suspension of quarterly dividends. By December 31, 2024, the program was largely completed, with the exception of the headquarters sale, which remains an active initiative with multiple interested parties. These efforts yielded tangible results, contributing to an expanded non-GAAP gross margin and a positive non-GAAP operating profit for the full year 2024, alongside a significant improvement in net cash provided by operating activities.

Further strengthening its financial foundation, ADTRAN appointed Tim Santo as its new CFO in early March 2025, bringing extensive experience in finance and operational leadership. On September 19, 2025, the company issued $201.30 million aggregate principal amount of 3.75% convertible senior notes due 2030, a strategic move designed to lower borrowing costs and enhance financial flexibility. Most recently, on November 3, 2025, ADTRAN terminated its deferred compensation plans to streamline benefits, reflecting an ongoing commitment to optimizing its capital structure and focusing on core growth opportunities.

Financial Performance: A Turnaround in Progress

ADTRAN's recent financial performance signals a clear turnaround, demonstrating the positive impact of its strategic initiatives and improving market conditions. For the third quarter of 2025, total revenue reached $279.4 million, marking a substantial 22.7% increase year-over-year and a 5% sequential rise. This represents the fifth consecutive quarter of sequential growth and the fourth consecutive quarter of year-over-year improvement, underscoring the company's building momentum.

Performance across segments and product categories in Q3 2025 was robust:

• Network Solutions revenue grew 28.1% year-over-year to $232.54 million, contributing 83.2% of total revenue. Its gross profit margin for the quarter was 34.2%.
• Services Support revenue increased 1.5% year-over-year to $46.89 million, with a gross profit margin of 59.1%.
• Optical Networking Solutions revenue surged 46.7% year-over-year and 15% sequentially to $103.49 million. This growth was primarily driven by strong momentum in Europe, including deployments with a new large service provider, and the addition of 15 new optical customers.
• Access Aggregation Solutions revenue rose 11.5% year-over-year to $74.81 million. While supported by fiber access investments, this was partially offset by the seasonal buying patterns of two major European customers, who are expected to resume activity late in Q4 2025 or early 2026. The company added 14 new customers in this category.
• Subscriber Solutions revenue increased 12.3% year-over-year and 21% sequentially to $101.14 million, fueled by demand for residential and wholesale applications and the acquisition of 18 new customers.
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Profitability metrics reflect this positive trajectory. The non-GAAP gross margin improved to 42.1% in Q3 2025, up both sequentially and year-over-year. Management's longer-term goal for non-GAAP gross margin is 43%, a target they anticipate "bumping up against next year." Non-GAAP operating profit reached $15.1 million, or 5.4% of revenue, exceeding the midpoint of the company's outlook. Both selling, general, and administrative (SG&A) and research and development (R&D) expenses, as a percentage of revenue, decreased year-over-year in Q3 2025, reflecting the benefits of the Business Efficiency Program and disciplined cost management.

Liquidity and cash flow generation have also seen significant improvement. Net cash provided by operating activities for the nine months ended September 30, 2025, was $87.5 million. Cash, cash equivalents, and restricted cash totaled $101.2 million as of September 30, 2025. Operational efficiency is evident in the Days Sales Outstanding (DSO), which improved from 67 days at the end of 2024 to 59 days by September 30, 2025. Inventory levels decreased by $14.5 million to $223.8 million over the same period, with inventory turnover increasing from 2.3 times to 3 times, moving closer to the company's target of 4 times. The company's debt structure includes $25 million under its revolving credit agreement and $201.30 million in convertible senior notes as of Q3 2025. ADTRAN aims to achieve a net positive cash position by the end of 2025, supported by ongoing asset monetization efforts, including the sale of its Huntsville campus.

Competitive Positioning: Gaining Ground in a Dynamic Market

ADTRAN operates in a highly competitive telecommunications equipment market, but its strategic focus and technological differentiators are enabling it to gain significant ground, particularly in Europe. The company is actively capitalizing on a "significant market share disruption" in Europe, positioning itself as a primary beneficiary of the displacement of certain incumbent vendors. This includes potential "rip and replace" opportunities, especially in Germany, where momentum is building, with optical solutions expected to see earlier traction than access.

The recent bankruptcy of DZS (DZSI) has also created a positive impact for ADTRAN, as the company has begun shipping to multiple former DZS customers in the U.S., with an estimated $10 million opportunity when fully realized. ADTRAN's integrated portfolio facilitates cross-selling, demonstrating success with Tier 3 customers who are adopting both access and transport solutions, and with larger Tier 2 carriers expanding their business to include ADTRAN's optical and Ethernet products.

Compared to larger, more diversified competitors such as Cisco Systems (CSCO), Nokia (NOK), Ericsson (ERIC), and Juniper Networks (JNPR), ADTRAN maintains a specialized, yet robust, market position. While these rivals offer broader portfolios and often possess greater scale, ADTRAN differentiates through its deep expertise in niche fiber innovations and customer-focused services. For instance, ADTRAN's focus on mid-network transport for regional optical networks provides a specialized edge. In fiber access, its SDX portfolio is highlighted as a "better product" due to its scalability, software-based architecture, and disaggregated nature. In subscriber solutions, differentiation is driven by software like Mosaic One and Intellifi, coupled with keeping pace with generational hardware changes like Wi-Fi 7.

ADTRAN's operational execution is a core competency, allowing it to compete effectively in its chosen segments. However, its smaller scale compared to industry giants could present vulnerabilities, potentially leading to higher costs or slower adaptation in certain broad technological areas. The company's customer concentration also implies a higher financial exposure to individual customer dynamics. Indirect competitors, including software-defined networking providers and satellite broadband services like Starlink, also pose a threat by offering alternative solutions that could impact demand for traditional fiber infrastructure. Despite these challenges, ADTRAN's strategic adaptability, evidenced by its diversified supply chain and active hedging strategies, aims to mitigate risks associated with trade policy changes and foreign currency fluctuations.

Outlook and Risks: A Path to Sustained Growth

ADTRAN's outlook reflects confidence in continued growth and profitability, underpinned by improving market conditions and strategic execution. For the fourth quarter of 2025, the company projects revenue between $275 million and $285 million, with a non-GAAP operating margin anticipated to be between 3.5% and 7.5%. Operating expenses are expected to remain relatively flat compared to Q3 2025. Management anticipates that two large European Access & Aggregation customers, whose buying patterns were seasonal in Q3, will "come back online either late in the fourth quarter or early next year." The company's strong momentum is expected to potentially overcome typical Q4 seasonal headwinds.

Looking further into 2026, ADTRAN expects continued operating margin expansion and earnings growth. The company targets achieving double-digit operating margins when its revenue reaches approximately $315 million on a constant currency basis. This growth is also expected to be supported by an improved spending environment from the Broadband Equity, Access, and Deployment (BEAD) Program, with orders anticipated in the first half of calendar 2026. ADTRAN's long-term operating targets include non-GAAP gross margins in the low-to-mid 40s and operating profit margins in the low double digits.

Despite this positive outlook, several risks warrant investor attention. The ongoing DPLTA appraisal proceedings in Germany could result in higher Exit or Annual Recurring Compensation payments to Adtran Networks shareholders, potentially impacting ADTRAN's financial position. The company has also identified material weaknesses in its internal control over financial reporting, leading to restatements of prior financial statements. While remediation efforts are underway, the failure to fully address these weaknesses could adversely affect investor confidence and business operations. Other risks include supply chain dependencies, the challenge of accurately matching inventory to demand, intense competition, rapid technological change, and the potential impact of evolving trade policies and tariffs. ADTRAN is actively managing these risks through supply chain diversification, hedging strategies for foreign currency exposure, and adherence to debt covenants under its Wells Fargo (WFC) Credit Agreement.

Conclusion

ADTRAN Holdings is demonstrating a compelling turnaround, strategically positioning itself at the forefront of global fiber and optical networking. The company's resurgence is driven by a powerful combination of technological innovation, particularly in its SDX fiber access platforms, 800 Gig optical transport, and AI-powered Mosaic One software, which are delivering quantifiable operational efficiencies and securing significant market share gains, especially across Europe. This technological leadership, coupled with disciplined operational execution and a strengthened capital structure, underpins a clear path to sustained profitability and enhanced shareholder value. While challenges such as DPLTA appraisal proceedings and internal control remediation persist, ADTRAN's proactive management of these risks and its focus on capitalizing on industry tailwinds like fiber expansion and AI-driven network upgrades suggest a promising trajectory for investors. The company's ability to convert its technological edge and strategic market penetration into consistent financial performance will be key to realizing its long-term targets of double-digit operating margins.