Korea-based artificial intelligence (AI) fabless (chip design) corporations Rebellions is understood to have logged about 35 billion won in annual revenue last year. Revenue surged about 3.4 times from the previous year (10,349.17 million won), putting the business on a full-fledged track. Founded in Sep. 2020, Rebellions began generating revenue in 2023. Annual revenue at the time was 2,734.77 million won, which means the business grew more than tenfold in two years.
According to reporting compiled by ChosunBiz on the 6th, Rebellions sold thousands of units of its first-generation Neural Processing Unit (NPU) products, ATOM and ATOM-Max, last year. Having successfully entered the market with its first mass-produced products, last year's revenue was tallied at around 35 billion won, up about 238% from the year before. Rebellions' first-generation NPU products are being used to run AI services at SK Telecom, KT Cloud, and LG Electronics, among others.
According to the Financial Supervisory Service's electronic disclosure system, Rebellions' annual revenue shown in the 2024 audit report is 10,349.17 million won. Rebellions merged with Sapeon Korea on Dec. 1, 2024, and when the combination date is adjusted to the start of the year, revenue comes to 15,644 million won. Even factoring in revenue added by the merger, last year's revenue grew about 2.2 times from a year earlier. A semiconductor industry official familiar with Rebellions' internal situation said, "Rebellions is currently conducting a settlement of account to prepare the 2025 audit report," adding, "Final figures will be compiled after the closing, but even on a conservative basis, last year's revenue increased more than threefold from the previous year."
Rebellions wrapped up its Series C last September, bringing cumulative investment to about 650 billion won. In the process, the corporations value was recognized at about 2 trillion won. Rebellions became Korea's first NPU fabless unicorn (a privately held startup valued at $1 billion or more) in 2024. In about a year, the corporations value grew roughly twofold again. Major investors in Rebellions include ▲Samsung (Samsung Venture Investment, Samsung Securities) ▲SK hynix ▲Arm ▲KT ▲SK Telecom ▲Saudi Aramco, earning it the nickname "Korea's leading AI Semiconductor player."
◇ Second-generation NPU to go into mass production this year… "Contributing to the advancement of the Korean semiconductor ecosystem"
Rebellions' semiconductors are particularly specialized in "inference" among the various areas of AI. Global big tech companies have so far focused on the process of "training" AI using graphics processing units (GPUs). But as AI services have recently entered the commercialization stage, "inference," which affects actual performance, is becoming more important. In this process, there is a trend of trying to lower service expense by using NPUs, which are more efficient than GPUs.
A representative example is Google's seventh-generation AI chip, the tensor processing unit (TPU), which it developed in-house and uses for its own AI inference. OpenAI, the developer of ChatGPT, also recently said it signed a $10 billion (about 14.709 trillion won) partnership with U.S. AI Semiconductor startup Cerebras to build an inference infrastructure 15 times faster than GPUs.
Park Sung-hyun, CEO of Rebellions, said at a press conference marking the fifth anniversary of its founding in Dec. last year, "I think the next five years will be a period when a new AI infrastructure system centered on non-Nvidia takes shape," adding, "Rebellions will be at the forefront leading this trend." The ambition is to take part of the market Nvidia holds in inference and deliver results.
Leveraging funds raised through its Series C, Rebellions developed its second-generation NPU, "REBEL-Quad," tailored to an AI market shifting toward inference, and has been mass-producing it since early this year. It has already secured buyers for some quantities. It is also conducting proofs of concept (PoC) with various big tech companies, expanding the potential for additional orders. The company says Rebel Quad delivers performance equal to or better than Nvidia's flagship GPU (H200) in inference-critical metrics such as "latency" and "compute."
To overcome the physical limit of semiconductor chip manufacturing, the "reticle limit" (Reticle Limit, 858㎟), Rebellions applied a "chiplet" process to Rebel Quad. It is also equipped with fifth-generation high-bandwidth memory (HBM3E), making it applicable to hyperscale data centers.
Shin Sung-kyu, chief financial officer (CFO) of Rebellions, said in a phone interview with a reporter, "The first-generation product is suitable for small and midsize AI models, and the second-generation product targets operation of large AI models," adding, "Revenue from sales of the first-generation product is expected to continue this year following last year. With the addition of second-generation mass production, we plan to broaden our customer base." He added, "Building on last year's results, we will step up as 'Korea's national flagship fabless' this year."
Except for part of the packaging process, Rebellions' second-generation AI chips are all made in Korea. They use Samsung Electronics' 4-nanometer (nm, one-billionth of a meter) foundry (contract chip manufacturing) process. The HBM is also domestically produced. This contrasts with other domestic NPU fabless corporations that use Taiwan's TSMC.
Kim Yang-paeng, a senior researcher at the Korea Institute for Industrial Economics & Trade (KIET), said, "Nvidia has virtually dominated the general-purpose AI field, but the NPU market used for specialized areas still offers opportunities," adding, "Rebellions is one of the few corporations in the world that can seize this chance, and rather than a simple fabless, it is meaningful as a company leading the success of the domestic semiconductor ecosystem." He added, "From development to production and real-world use, everything is done domestically, making a significant contribution to building independent competitiveness that does not depend on Nvidia," and "Based on domestic validation cases, it is also accelerating overseas expansion, which is a positive factor for expanding the domestic ecosystem."
However, some in the industry say Rebellions' results last year fell short of expectations. That is because at the end of 2024 Rebellions presented a 2025 annual revenue target of "more than 100 billion won" and a roadmap to push for an initial public offering (IPO) in the first half of 2025. With results coming in at less than half that goal, some analyze that the IPO may not be as successful as the market initially expected. Rebellions is said to have selected Samsung Securities as the lead underwriter and plans to conduct an IPO late this year to early next year. A semiconductor industry official said, "Rebellions' business is growing rapidly, but there are also assessments that results fall short compared with the messages it has sent to the market," adding, "Such differences in view could affect the IPO."