Deep Fission is seeking to raise approximately $150 million in an initial public offering expected to begin trading on May 29, 2026. The company plans to list on the Nasdaq under the ticker symbol “FISN” and is offering 6.0 million shares at an indicated range of $24.00 to $26.00 per share, implying a midpoint deal size of approximately $150 million and a fully diluted valuation near $1.6 billion. The offering is being led by BofA Securities, Morgan Stanley, and Canaccord Genuity.
Founded in 2023 by Elizabeth Muller and Richard Muller, Deep Fission is attempting to differentiate itself within the increasingly crowded small modular reactor (“SMR”) market through its underground “Gravity Reactor” design. The company’s concept places compact pressurized water reactors approximately one mile underground inside deep boreholes, which management believes could materially reduce construction complexity, containment infrastructure, and overall deployment costs compared to traditional nuclear facilities.
Unlike several advanced nuclear developers pursuing High-Assay Low-Enriched Uranium (“HALEU”), Deep Fission plans to utilize standard Low-Enriched Uranium (“LEU”), which could provide an advantage given ongoing HALEU supply constraints and fuel availability concerns across the nuclear industry. The company is positioning its technology primarily around powering hyperscale AI data centers, industrial infrastructure, utilities, and other high-demand electricity applications requiring stable carbon-free baseload generation.
One aspect that may draw investor attention is the company’s prior path to the public markets. In September 2025, Deep Fission previously completed a reverse merger transaction with Surfside Acquisition Inc., raising approximately $30 million through a concurrent private placement priced at $3.00 per share. Following the transaction, Surfside Acquisition formally changed its name to Deep Fission, Inc. and became a public reporting company.
According to SEC filings tied to the transaction, legacy Deep Fission shareholders received approximately 38.5 million shares in the merger, while Surfside shareholders retained roughly 2.17 million shares prior to additional financing activity. The reverse merger was structured as a recapitalization transaction that effectively allowed Deep Fission to enter the public markets more quickly than through a traditional IPO process.
The earlier Surfside transaction received mixed reactions within portions of the nuclear and investing communities, particularly given the relatively modest amount of capital raised versus the substantial funding requirements typically associated with advanced reactor development. Some industry observers questioned whether the company would ultimately require significantly larger future financings to support commercialization and regulatory efforts.
Still, Deep Fission has continued attracting investor interest amid broader enthusiasm surrounding nuclear infrastructure tied to artificial intelligence power demand. The company has highlighted participation in the Department of Energy’s Reactor Pilot Program and has stated ambitions to begin deployment of its first underground reactor system as early as 2026, though commercialization timelines for advanced nuclear technologies often remain fluid and subject to regulatory approvals, engineering milestones, and financing conditions.
As with many early-stage nuclear developers, investors will likely focus heavily on licensing timelines, drilling feasibility, engineering validation, capital requirements, and the company’s ability to scale beyond demonstration projects. Deep Fission currently remains pre-revenue and will require substantial additional capital to advance commercialization efforts, but the transaction nonetheless arrives during one of the strongest periods for nuclear investor sentiment in years as markets increasingly search for scalable long-duration energy solutions capable of supporting rapidly expanding AI-related electricity consumption.