FISN Investors Have Opportunity to Join Deep Fission, Inc. Fraud Investigation with SBS Law. LOS ANGELES-(BUSINESS WIRE)-Schall, Brown & Schwartz LLP ("SBS"), a national shareholder rights litigation firm, announces that it is investigating claims on behalf of investors of Deep Fission, Inc. ("Deep Fission" or "the Company") (NASDAQ: FISN) for violations of the securities laws. INVESTIGATION DETAILS: The investigation focuses on whether the Company issued false and/or misleading statements and/or failed to disclose information pertinent to investors. Deep Fission conducted its initial public offering ("IPO") on June 18, 2026, selling 2.5 million shares of stock at $16.00 per share. The Company is the subject of a report published by Iceberg Research on September 26, 2026, that claims the Company's technology is overhyped and unlikely to become commercially viable. Based on this news, shares of Deep Fission fell sharply. Business Wire, Inc. also encourage you to contact Brian Schall or David Schwartz of Schall, Brown & Schwartz LLP, 2049 Century Park East, Suite 2460, Los Angeles, CA 90067, at 310-301-3335, to discuss your rights free of charge. You can also reach Business Wire, Inc. through the firm's website at www.schallfirm.com, or by email at [email protected]. WHY SBS? Schall, Brown & Schwartz LLP represents investors around the world and specializes in securities class action lawsuits and shareholder rights litigation. Bringing together the extensive experience and diverse skillsets of founding partners Brian Schall, Andrew Brown, and David Schwartz, SBS is dedicated to aggressively advocating for every investor. Contacts. Schall, Brown & Schwartz LLP Brian Schall, Esq., Andrew Brown, Esq., David Schwartz, Esq., www.schallfirm.com Office: 310-301-3335 [email protected] More News From Schall, Brown & Schwartz LLP LOS ANGELES-( BUSINESS WIRE )-KGC Investors Have Opportunity to Join Kinross Gold Corporation Fraud Investigation with SBS Law... LOS ANGELES-( BUSINESS WIRE )-FLUT Investors Have Opportunity to Join Flutter Entertainment plc Fraud Investigation with SBS Law... LOS ANGELES-( BUSINESS WIRE )-NCPL Investors Have Opportunity to Join Netcapital Inc. Fraud Investigation with SBS Law... Schall, Brown & Schwartz LLP. NASDAQ:FISN Release Summary Release Versions Schall, Brown & Schwartz LLP Brian Schall, Esq., Andrew Brown, Esq., David Schwartz, Esq., www.schallfirm.com Office: 310-301-3335 [email protected]

Deep Fission ($FISN): a money pit. September 24, 2026 Please refer to its disclaimer at the bottom of the report. Main findings * Nasdaq-listed Deep Fission (FISN) is developing a small modular reactor (SMR) with a capacity of 5MWe-15MWe. The company plans to bury a miniature version of the widely used pressurized water reactor (PWR) one mile deep, inside a 40-60-inch water-filled borehole drilled into hard rock. * Like other SMR developers, FISN pitches itself as an AI data-center power solution. But data centers have turned to natural gas to accelerate deployment. Almost all of the roughly 75GW of booked data center on-site generation is natural gas-based. FISN has no regulatory approval and remains years away from commercialization. * Before its June 2026 IPO, FISN guided to a levelized cost of energy (LCOE) of just $50-70/MWh. Then the company dropped the reference. Using figures disclosed in its June 2026 prospectus, Three Mile Island Alert calculate an LCOE of $289/MWh for the first-of-a-kind (FOAK) reactor and $148/MWh for the nth-of-a-kind (NOAK) reactor, about 200% above prior guidance. This is not competitive with behind-the-meter gas solutions. * Even this NOAK estimate is too optimistic, as capital cost is understated. Using figures from independent third parties, Three Mile Island Alert estimate NOAK capital cost to be $112mn, 34% above FISN's estimate, raising its estimated NOAK LCOE to $170/MWh. * FISN claims it can secure Nuclear Regulatory Commission (NRC) approval in less than a year. Yet it has already struggled with the less demanding Department of Energy (DOE) process, missing the program deadline while at least four peers have already completed it. Even if NRC approved, commercialization is far from assured: NuScale, which has a much more conventional design, has yet to sell a reactor three years after receiving its NRC license. * FISN targets deploying its reactor in just six months versus 3-4 years for other advanced SMRs, citing fewer safety-related systems. Yet its own filing states a two-year development timeline. Peers pursue the same simplification strategy, but FISN adds a major step: drilling a one-mile borehole. * FISN touts the industry's largest customer pipeline. Most counterparties are undisclosed. Of those identified, one is an undeveloped industrial park with doubtful demand for a nuclear reactor. The other two (Endeavour Energy and Blue Owl) have signed only non-binding agreements. * FISN has less than twelve months of cash runway and faces ~$350mn of unfunded capital needs, potentially implying ~43% dilution to its existing shareholders. At the same time, the competition for SMR funding is intensifying: publicly traded SMR names have risen from three before October 2025 to nine today, with three more coming to the market, including a far more established player, Westinghouse. * FISN is largely a repackaging of the founders' prior venture, Deep Isolation, a deep-borehole nuclear waste disposal company that has failed to commercialize its concept after a decade. Background and bull case Deep Fission (NASDAQ: FISN) is a California-headquartered company founded in 2023. The company is developing a nuclear reactor called Gravity. The reactor is intended to be a miniature version of the conventional pressurized water reactor (PWR), using low-enriched uranium (LEU) as fuel. The company's key innovation is that its reactor would be buried in a 40-60-inch water-filled borehole one mile (~1.6 km) underground. The reactor is designed with a power generation capacity of 5-15MWe. Management claims that its reactor is cheaper to build because its innovative borehole design eliminates certain components required in above-ground PWR reactors. For example, the depth and surrounding geology provide natural containment, potentially eliminating the need for the reinforced concrete and steel containment structures typical of above-ground reactors. FISN was founded by Richard Muller, a UC Berkeley physics professor, and his daughter Elizabeth, who serve as CTO and CEO of the company, respectively. The company became an unquoted public company in September 2025 through a reverse merger with shell company Surfside Acquisition, before listing on Nasdaq in June 2026. FISN is participating in the Department of Energy's (DOE) pilot reactor program. The company is seeking DOE authorization to build a pilot reactor at a site in Parsons, Kansas, by 1H 2027. Then, FISN plans to submit license applications to the Nuclear Regulatory Commission (NRC) to convert the pilot reactor into a commercial facility by the end of 2027, with high-volume deployment targeted to begin in 2028. Because its reactor is based on well-established PWR technology, its licensing pathway would be simpler than for novel advanced reactor designs. The company claims that its reactor can then be commercially deployed in as little as six months, compared with three to four years for other small modular reactors (SMR). FISN expects the surge in power demand from AI data centers will drive demand for its reactors and claims the largest pipeline of potential customers, representing 18.5GW of prospective capacity. It's time for small modular reactor supporters to admit it: natural gas, not SMRs, is the undisputed winner of the AI data center build-out In early 2024, the market realized that AI would consume enormous amounts of energy. This kicked off a trading frenzy from conventional nuclear, to gas-turbine manufacturers, to the speculative (and often sketchy) SMR companies. Every player, including the most exotic concept, was supposed to win. Fast forward two years, and the verdict is in. Gas-fired generation is the clear preferred solution for powering AI infrastructure. Data centers have booked 75GW of onsite generation capacity so far. Almost all of them will rely on natural gas. While the largest and most efficient combined-cycle gas turbines face multi-year lead times, data centers have turned to smaller engines or aeroderivatives with lead times as short as twelve months. Gas generation is a proven technology and can meet AI power demand quickly, with the added advantage of cheap natural gas in the US. SMRs, on the other hand, sit at exactly the opposite end of the spectrum: they remain unproven, with commercialization not expected before the 2030s. Submitted by admin on Mon, 09/28/2026 - 19:16

Deep Fission and Youngquist Brothers announce collaboration on deep, large-diameter borehole drilling for underground Nuclear Reactor deployment. - Companies will jointly evaluate and test drilling and borehole-construction methods to support Deep Fission's underground reactor technology - Published on 09/21/2026 at 07:31 am EDT Business Wire Deep Fission, Inc. (Nasdaq: FISN) ("Deep Fission" or the "Company"), an advanced nuclear energy company working to place small modular pressurized water reactors (SMRs) in boreholes approximately one mile underground, today announced a collaboration with Youngquist Brothers, LLC ("Youngquist"), a commercial drilling contractor specializing in large-diameter boreholes, to evaluate and test drilling technologies for Deep Fission's underground reactor deployment model. Deep Fission and Youngquist Brothers are collaborating to advance deep, large-diameter borehole drilling for Deep Fission's underground reactor deployment model. Under the collaboration, the companies will advance and test methods for constructing large-diameter, deep boreholes for Deep Fission's underground deployment model, drawing on Youngquist's drilling and borehole-construction expertise. On September 3, the companies successfully completed a related equipment demonstration in Fort Myers, Florida, where Deep Fission lowered and retrieved its 30-inch full-size prototype reactor canister into a 34-inch borehole, to a depth of approximately 100 feet using Youngquist's proprietary drilling technologies & equipment. The demonstration scale test focused on installation and retrieval mechanics, distinct from the full-depth drilling work intended to be covered by the collaboration. "Youngquist brings decades of hands-on drilling experience that maps directly onto what our deployment model requires," said Liz Muller, CEO and Co-Founder of Deep Fission. "Working with an established commercial driller lets us advance the drilling side of our approach using equipment and expertise that already exist in the field, rather than starting from scratch." Youngquist has spent decades drilling large-diameter boreholes reaching depths of more than 8,000 feet. That experience gives the collaboration a strong foundation for adapting proven commercial drilling methods to Deep Fission's underground deployment model. "Large-diameter drilling to these depths is a method we've refined since 1971," said Harvey Youngquist, CEO of Youngquist Brothers. "What Deep Fission requires for its nuclear application is the same discipline we've always applied. We're glad to bring that experience to a project of this scale and in this unique application." Deep Fission's Gravity(TM) Nuclear Reactor uses established pressurized water reactor technology and standard low-enriched uranium fuel and secures the reactor roughly a mile underground in a water-filled borehole. The surrounding rock and water are designed to provide core safety and operating functions, including containment and cooling. The collaboration with Youngquist is focused on the drilling and borehole-construction methods needed to support that underground deployment. The companies intend to continue working together on borehole drilling and testing as Deep Fission advances toward commercial deployment, which the Company is targeting as early as 2027. About Deep Fission Deep Fission is developing technology that places a small modular pressurized water reactor in a borehole approximately one mile underground. The Company's Gravity Nuclear Reactor(TM) approach combines established pressurized water reactor technology with a novel underground deployment model designed to simplify construction, enhance safety, and support scalable commercial deployment. Deep Fission is focused on delivering reliable, low-carbon baseload power to meet growing electricity demand from utilities, industrial customers, and data centers. The Company is currently advancing the development of its first reactor project in Parsons, Kansas and was selected for the U.S. Department of Energy's Reactor Pilot Program. Forward Looking Statements This press release contains forward-looking statements within the meaning of the federal securities laws. Forward-looking statements include, but are not limited to, statements regarding the scope, objectives, continuation and anticipated benefits of the collaboration; the parties' plans to advance and test technologies and construction methods; the applicability and adaptability of Youngquist's equipment, expertise and commercial methods to the Company's deployment model; the anticipated effect of the collaboration on advancing the drilling aspects of the Company's approach; and the Company's progress toward and anticipated timing of commercial deployment, including its target as early as 2027. These statements are based on current expectations and assumptions and are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied. Important factors that may cause actual results to differ materially include, among others, risks related to the parties' ability to continue and successfully perform the collaboration; changes in the scope, timing or objectives of the collaboration; the ability to adapt existing equipment, technologies and construction methods to the Company's proposed application and deployment model; technical, engineering, drilling, construction, regulatory, licensing, financing, supply chain, and deployment risks; and the other risks described under "Risk Factors" and "Cautionary Note Regarding Forward-Looking Statements" in Deep Fission's filings with the Securities and Exchange Commission. Forward-looking statements speak only as of the date of this press release. Deep Fission undertakes no obligation to update any forward-looking statements, except as required by law. View source version on businesswire.com: https://www.businesswire.com/news/home/20260921829551/en/ (C) Business Wire - 2026