Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-41013 GCT Semiconductor Holding, Inc. (Exact name of Registrant as specified in its Charter) | Delaware | 86-2171699 | | --- | --- | | (State or other jurisdiction of | (I.R.S. Employer | | incorporation or organization) | Identification No.) | | 2290 North 1s ...

Exhibit 99.1 GCT Semiconductor Holding, Inc. Provides Business Update and Reports Fourth Quarter and Full Year 2025 Financial Results Commercial Shipments of 5G Chipsets Exceeded 1,900 Units in Q4, Reflecting Continued Progress Toward Volume Production Ramp Company Expects Sequential Quarterly Growth in Revenue and 5G Chipset Shipments Throughout 2026 SAN JOSE, CA – March 25, 2026 – GCT Semiconductor Holding, Inc. ("GCT" or the "Company") (NYSE: GCTS), a leading designer and supplier of advanced 5G and 4G s ...

Financial Performance - GCT Semiconductor reported initial 5G product revenue of $0.4 million in Q3 2025, an 84.0% decrease from $2.6 million in Q3 2024[11] - Total operating expenses increased by 9.0% to $8.2 million in Q3 2025, compared to $7.5 million in Q3 2024[11] - GCT's net loss for Q3 2025 was $13.8 million, compared to a net loss of $7.1 million in Q3 2024[11] - The gross margin for Q3 2025 is negative, as current product revenue is insufficient to cover production overhead costs[11] 5G Product Development - The company has received over 2,500 initial 5G chipset orders, indicating strong early demand as it prepares for commercialization[5] - GCT expects to improve operational efficiencies as volume shipments of 5G products begin in late Q4 2025 or early Q1 2026[3] - The company anticipates commercial shipments of 5G chipsets to commence late in Q4 2025[7] Financial Position - As of September 30, 2025, GCT had cash and cash equivalents of $8.3 million, net accounts receivable of $3.7 million, and inventory of $1.9 million[6] - GCT's total assets increased to $24.3 million as of September 30, 2025, up from $19.9 million at the end of 2024[15] - The company secured $10.7 million in debt financing in September 2025 to accelerate production readiness for 5G chipsets[5]

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________ to ___________ Commission File Number: 001-41013 GCT Semiconductor Holding, Inc. (Exact Name of Registrant as Specified in its ...

Product Development and Launch - The company anticipates the commercial launch of its 5G products in the second half of 2025, with average sales prices expected to be approximately four times that of its 4G chipsets, leading to a significant increase in revenue and gross margins [155]. - The company has delivered initial samples to lead 5G customers in Q2 2025, indicating progress in product development and customer engagement [155]. - The company expects to continuously expand its product lineup to support future applications such as vehicle-to-everything standards and 5G-based IoT standards [155]. - The company expects operational efficiencies to improve as revenues increase, particularly with the anticipated contribution of 5G product sales in the second half of 2025 [206]. - The company expects to launch its 5G products commercially in the second half of 2025, following the delivery of initial samples to lead customers [225]. Financial Performance - Net revenues decreased by $0.3 million, or 19%, from $1.5 million for the three months ended June 30, 2024 to $1.2 million for the three months ended June 30, 2025 [186]. - Product sales increased by $0.4 million, or 2,167%, from $0.018 million for the three months ended June 30, 2024 to $0.408 million for the three months ended June 30, 2025 [186]. - Service revenues decreased by $0.7 million, or 47%, from $1.5 million for the three months ended June 30, 2024 to $0.8 million for the three months ended June 30, 2025 [188]. - Gross profit decreased by $543,000, or 59%, from $921,000 for the three months ended June 30, 2024 to $378,000 for the three months ended June 30, 2025 [186]. - Net loss increased by $12.5 million, or 1,198%, from a net loss of $1.0 million for the three months ended June 30, 2024 to a net loss of $13.5 million for the three months ended June 30, 2025 [186]. - The company reported a net loss of $20.5 million for the six months ended June 30, 2025, compared to cash used in operating activities of $24.1 million for the same period in 2024 [218]. Operating Expenses - The company anticipates an increase in general and administrative expenses due to growth and the costs associated with operating as a public company [177]. - General and administrative expenses increased by $0.4 million, or 6%, from $5.7 million for the six months ended June 30, 2024, to $6.0 million for the six months ended June 30, 2025 [209]. - Total operating expenses remained relatively stable, decreasing by $30,000, or 0%, from $8.0 million for the three months ended June 30, 2024 to $7.97 million for the three months ended June 30, 2025 [186]. - Research and development expenses decreased by $0.7 million, or 16%, from $4.2 million for the three months ended June 30, 2024 to $3.5 million for the three months ended June 30, 2025 [193]. Cash Flow and Financing - Cash used in operating activities was $16.6 million for the six months ended June 30, 2025, primarily due to the net loss and non-cash adjustments of $2.3 million [233]. - Cash used in operating activities was $24.1 million for the six months ended June 30, 2024, primarily due to a net loss of $0.3 million and non-cash adjustments of $12.5 million [235]. - Cash provided by financing activities was $27.9 million for the six months ended June 30, 2024, including $17.2 million from reverse recapitalization and PIPE Financing [238]. - Cash provided by financing activities was $16.1 million for the six months ended June 30, 2025, consisting of $11.0 million from common stock issuance [237]. - The company sold an aggregate of 2,438,737 shares of common stock for $9.9 million under an equity line of credit facility through June 30, 2025 [219]. - The registered direct offering in May 2025 generated approximately $11.0 million in gross proceeds from the sale of 7,006,370 shares of common stock and warrants [221]. Industry and Market Conditions - The semiconductor industry is experiencing cyclicality, with potential downturns affecting demand, production overcapacity, and pricing pressures [163]. - The company’s largest customer shifted focus from 4G to 5G products due to supply shortages, impacting demand for its 4G products [168]. - Revenue is generated from mobile semiconductor solutions aimed at the LTE and 5G industries, with revenue recognition dependent on the transfer of control to customers [246]. Risks and Commitments - The company relies on third-party foundries for manufacturing, with no formal agreements guaranteeing minimum capacity, which poses risks during periods of high demand [165]. - The company has material commitments and contractual obligations related to leases and research and development agreements [239]. - The company has certain debt agreements related to convertible promissory notes and borrowings [241]. - The provision for credit losses increased to $2.6 million as of June 30, 2025, compared to $1.2 million as of December 31, 2024 [249]. Other Financial Metrics - Interest expense increased by $0.8 million, or 102%, from $0.8 million for the three months ended June 30, 2024 to $1.5 million for the three months ended June 30, 2025 [196]. - Interest expense decreased by $0.2 million, or 8%, from $2.8 million for the six months ended June 30, 2024, to $2.6 million for the same period in 2025 [211]. - The gain on extinguishment of liability was $14.6 million for the six months ended June 30, 2024, with no similar transactions in 2025 [210]. - Non-cash adjustments in operating activities included a $14.6 million gain from extinguishment of a liability [235]. - The company is classified as an "emerging growth company" under the JOBS Act, allowing it to delay adopting new accounting standards [254].

Financial Performance - Net revenues for Q2 2025 were $1.2 million, a 19.0% decrease from $1.5 million in Q2 2024[4] - Total net revenues for Q2 2025 were $1.182 billion, a decrease of 19.5% compared to $1.468 billion in Q2 2024[18] - Gross profit for the six months ended June 30, 2025, was $466 million, down from $2.874 billion in the same period of 2024[18] - The net loss for Q2 2025 was $13.538 million, compared to a net loss of $1.043 million in Q2 2024[18] - Basic and diluted net loss per common share for Q2 2025 was $0.26, compared to $0.02 in Q2 2024[18] - Loss before provision for income taxes for Q2 2025 was $13.499 billion, compared to a loss of $0.976 billion in Q2 2024[18] Operating Expenses - Total operating expenses remained unchanged at $8.0 million[12] - Operating expenses for Q2 2025 totaled $7.970 billion, slightly down from $8.000 billion in Q2 2024[18] - Research and development expenses for the six months ended June 30, 2025, were $7.610 billion, down from $9.685 billion in the same period of 2024[18] Cash and Assets - Cash and cash equivalents as of June 30, 2025, were $1.3 million, with net accounts receivable of $3.8 million and inventory of $3.0 million[6] - The company has approximately $114 million of remaining availability under its $200 million shelf registration statement[6] 5G Chipset Development - The company expects to commence production of finalized 5G chipsets in Q3 2025, with volume shipments starting in Q4 2025[7] - Initial 5G chipset samples were delivered to key customers, including Orbic North America and Airspan Networks, with successful milestone testing reported[5] - The partnership with Iridium Communications Inc. aims to integrate the Iridium NTN Direct℠ service into GCT's GDM7243SL chipset, expanding into the non-terrestrial market[5] - The company is collaborating with Giesecke+Devrient to launch innovative eSIM solutions for IoT devices[5] Financial Offerings - The company completed an $11 million registered direct offering to fund 5G chipset sampling and debt retirement[5] Gross Margin - Gross margin decreased to 32.0%, down 30.7 percentage points from 62.7%[12] Interest Expense - Interest expense for Q2 2025 was $1.532 billion, an increase from $0.760 billion in Q2 2024[18] Shares Outstanding - The weighted average common shares outstanding for Q2 2025 were 51,703 million, compared to 44,060 million in Q2 2024[18] Cost of Revenues - Total cost of net revenues for the six months ended June 30, 2025, was $1.212 billion, compared to $1.859 billion in the same period of 2024[18]

GCT Semiconductor Holding, Inc. Provides Business Update and Reports First Quarter 2025 Financial Results 5G chipset sampling to customers scheduled to begin at the end of May, following completion of fab, wafer processing and delivery of finalized 5G chipsets to GCT facility SAN JOSE, CA – May 14, 2025 – GCT Semiconductor Holding, Inc. ("GCT" or the "Company") (NYSE: GCTS), a leading designer and supplier of advanced 5G and 4G semiconductor solutions, today provided an update on business developments and r ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ___________ to ___________ Commission File Number: 001-41013 GCT Semiconductor Holding, Inc. (Exact Name of Registrant as Specified in its Cha ...

Company Overview - GCT Semiconductor is a fabless semiconductor company specializing in communication semiconductors, including 5G, 4.75G, 4.5G, and 4G transceivers and modems[22]. - The company has established a fabless semiconductor business model, utilizing third-party foundries like Samsung Foundry for 28nm and 8nm production processes, which are expected to enhance cost-effectiveness and power consumption[78]. - The company has a robust quality assurance system in place, adhering to ISO 9001:2015 standards, ensuring product reliability and quality throughout the production cycle[81]. 5G Technology and Products - The company expects to introduce its 5G products in the first half of 2025, with average sales prices for 5G chipsets projected to be approximately four times that of 4G chipsets, significantly increasing revenue and gross margins[28]. - 5G technology offers speeds up to ten times faster than traditional 4G LTE, with capabilities essential for the Fourth Industrial Revolution, including applications in AI, autonomous driving, and the metaverse[26]. - The company is developing RF and modem chipsets for 5G, leveraging patented technology that enhances performance through multiple antennas for transmission and reception[27]. - The company plans to expand its product lineup to support future applications such as vehicle-to-everything standards and 5G-based satellite communication[28]. - The company expects to launch several 5G NR solutions during 2025, including products with advanced features such as 16Rx/4Tx and 8Rx/2Tx configurations[58][59]. - The company plans to offer three different 5G chipset solutions tailored to market demands, differentiating itself from dominant providers by offering customized solutions[52]. Market Trends and Demand - Fixed Wireless Access (FWA) services based on 4G and 5G have exceeded 130 million subscriptions as of the end of 2023, projected to grow at an annual rate of 17% to over 330 million by 2029[40]. - 5G-based FWA services are expected to surpass 4G-based subscriptions by 2025, constituting 85% of total FWA services by 2029[40]. - The deployment of 5G networks for FWA is facilitated by existing 5G infrastructure, making it an attractive growth driver for mobile service providers[44]. - The company is focusing on specific segments in the 5G markets, including fixed wireless access, mobile broadband, and M2M applications, which are critical for financial performance[94]. Financial Performance and Challenges - The company reported a net loss of $12.4 million for the year ended December 31, 2024, compared to a net loss of $22.5 million for 2023, indicating a reduction in losses[132]. - Cash used in operating activities was $31.0 million for 2024, down from $8.8 million in 2023, reflecting ongoing financial challenges[132]. - The accumulated deficit increased to $562.0 million in 2024 from $549.7 million in 2023, highlighting ongoing financial struggles[132]. - The company has dedicated a large portion of its operating expenses to the development of 5G products, with significant revenue expected only in the second half of 2025[109]. - The company anticipates ongoing cyclicality in semiconductor solution sales due to inherent industry fluctuations and seasonal slowdowns, particularly in Asia during the Lunar New Year, which may impact first-quarter sales[60]. Customer Relationships and Sales Strategy - The company maintains close relationships with wireless carriers and OEMs/ODMs, focusing on securing design wins for wireless broadband devices, with a sales cycle typically taking 12 months or more[68][72]. - Four customers accounted for 74% of total revenues for the year ended December 31, 2024, while two customers accounted for 38% for the year ended December 31, 2023[111]. - The company employs a dual-pronged market approach focusing on both operators and OEM/ODM customers to facilitate design wins[102]. Intellectual Property and Competitive Position - As of December 31, 2024, the company holds approximately 86 patent rights related to 5G/4G and next-generation wireless communication semiconductor technology, with 55% focused on modem design-related technologies[75]. - The company holds 33 US patents and 35 Korean patents, but faces challenges in protecting its intellectual property effectively[140]. - The company has secured a strong competitive position in the mobile communication market by providing optimized solutions amidst high technological barriers[46]. Operational Risks and Industry Challenges - The company faces competition from established semiconductor companies, which may impact its ability to maintain or increase market share[103]. - The semiconductor business faces ongoing competitive pricing pressure, and any increase in manufacturing costs could reduce gross margins and operating profit[122]. - The company may encounter difficulties in meeting obligations under development agreements, which could delay product shipments and adversely affect financial results[92]. - Geopolitical events and uncertainties could disrupt sales and product delivery, adversely affecting business operations[129]. - The wireless communications industry has faced pronounced downturns, which could adversely affect demand for the company's products[170]. Future Outlook and Growth Plans - The company plans to continuously expand its product lineup to support future applications such as vehicle-to-everything (C-V2X) and 5G-based satellite communication[53]. - The company expects to commence volume shipment of 5G chipsets in the first half of 2025, which is anticipated to generate significant revenue and improve financial performance[91]. - The company has entered into 5G development agreements with Tier 1 wireless communications operators, which include milestone payments upon achieving specified business and development objectives[91]. Compliance and Regulatory Environment - Compliance with governmental laws and regulations is critical, as noncompliance could lead to significant penalties and operational disruptions[196]. - Changes in laws regulating wireless networks and radio frequency emissions could adversely impact product sales and business operations[174]. - The company is subject to risks related to its ability to generate sufficient revenue or become profitable, which could necessitate seeking additional funding[133]. Human Resources and Talent Acquisition - The company employs 121 full-time employees as of December 31, 2024, with a significant focus on research and development, comprising 76 employees[82]. - The loss of key personnel could harm the business, and attracting and retaining specialized talent is critical for growth[206]. - The company plans to recruit design and application engineers with expertise in wireless communications technologies to support anticipated growth[207].

GCT Semiconductor Holding, Inc. Provides Business Update and Reports Fourth Quarter and Full Year 2024 Financial Results GCT launches "2025GCT" program to commence "Year of 5G" and celebrate upcoming 5G chipset shipments SAN JOSE, CA – March 25, 2025 – GCT Semiconductor Holding, Inc. ("GCT" or the "Company") (NYSE: GCTS), a leading designer and supplier of advanced 5G and 4G semiconductor solutions, today provided an update on business developments and reported financial results for the fourth quarter and f ...