FISN · Deep Fission, Inc. Common Stock

Summary

Deep Fission, Inc. develops the Gravity Reactor, a compact pressurized water reactor (PWR) placed 1-mile underground leveraging natural geology for containment, safety, and cooling, producing 15 MWe per unit with modular scaling to 1.5 GW clusters for hyperscale data centers, AI workloads, and industrial users. Incorporated in Delaware in July 2023 and co-founded by Richard Muller and Elizabeth Muller, the company was selected in August 2025 for the U.S. DOE Nuclear Reactor Pilot Program to demonstrate criticality by July 2026 at Great Plains Industrial Park in Parsons, Kansas, under an Other Transaction Agreement effective November 14, 2025. Legacy Deep Fission merged with shell company Surfside Acquisition Inc. on September 5, 2025, in a reverse recapitalization, issuing 38,538,922 shares to Legacy Deep Fission holders; Surfside shareholders retained 2,166,667 shares. Concurrently, a 2025 Private Placement raised $30 million (10 million shares at $3.00), followed by a 2026 Private Placement of 5,333,333 shares at $15.00 for $80 million. This S-1 registers resale of 5,462,751 shares by selling stockholders (PIPE shares and warrant shares), with no proceeds to the company except up to $1.94 million from warrant exercises for working capital and pilot reactor R&D. Pre-merger, nine-month net loss to September 30, 2025 was $47.5 million on $12.3 million expenses, with $30.2 million cash and $56.2 million accumulated deficit; auditor notes going concern doubt. Investment thesis centers on DOE validation, IP portfolio (1 patent, 24 applications), and nuclear demand from AI/data centers, targeting pilot criticality in 2026 and commercial deployments from 2028.

Key takeaways

• Develops underground Gravity Reactor (15 MWe/unit, scalable to 1.5 GW) using proven PWR tech for data centers/AI; selected for DOE Nuclear Reactor Pilot Program on August 12, 2025, targeting criticality by July 2026.
• Merger with Surfside on September 5, 2025 issued 38,538,922 shares to Legacy Deep Fission holders; 2025 Private Placement raised $30 million (10M shares at $3.00); 2026 Private Placement raised $80 million (5.33M shares at $15.00).
• S-1 registers resale of 5,462,751 shares by selling stockholders (5.33M PIPE + 129K warrant shares); company receives no proceeds except up to $1.94M from warrant exercises for pilot reactor R&D.
• Nine months ended September 30, 2025: $47.5M net loss, $12.3M operating expenses, $30.2M cash, $56.2M accumulated deficit; expects $105M pilot costs over next 12 months.
• IP: 1 issued U.S. patent (exp. 2043), 24 pending applications; 44 employees + 11 consultants as of prospectus date; non-binding LOIs for up to 12.5 GW capacity.
• Key risks: unproven technology, regulatory delays (NRC licensing post-DOE pilot), no binding customer contracts, ongoing losses and going concern doubt, public opposition to nuclear.