Here are the 424B prospectus supplements from Deep Fission, Inc. (FISN) in our archive over the last 12 months, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A 424B covers the supplement that carries the terms of a priced offering, so if you follow FISN and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full FISN filings page.
Deep Fission, Inc. is offering 2,500,000 shares of common stock at a public offering price of $16.00 per share, for gross proceeds of $40,000,000 and estimated proceeds to the company of $37,200,000 before expenses. The underwriters have a 30-day option to purchase up to 375,000 additional shares. Delivery is expected on or about June 22, 2026.
The prospectus describes Deep Fission’s subsurface small modular Gravity Reactor concept, its phased deployment plan (pilot demonstration under the DOE Reactor Pilot Program, NRC licensing plans, and commercial scale targets), and reactor-level conceptual economics and assumptions for 2x2 and 3x3 fuel configurations. The filing discloses a restatement of previously issued financial statements (identified April 9, 2026) related to SAFE valuations and stock-based compensation and reports material weaknesses in internal control over financial reporting as of March 31, 2026. The offering includes non-binding Cornerstone Investor interest aggregating up to $10 million at the public offering price.