---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-26-076400"
form_type: "8-K"
ticker: "FISN"
cik: "0001918102"
company_name: "DEEP FISSION, INC."
filed_at: "2026-06-22T20:20:56+00:00"
generated_at: "2026-06-22T20:23:10.455830+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Deep Fission completes IPO, raises $40M at $16.00 per share; stock begins trading on Nasdaq

## Summary
- Offered 2.5M shares at $16.00/share; gross proceeds of $40M.
- Underwriters have 30-day option to purchase up to 375,000 additional shares.
- Stock began trading on Nasdaq Global Market on June 18, 2026 under symbol FISN.
- Net proceeds to fund working capital, engineering, R&D, licensing, and construction of first pilot nuclear reactor.

## SEC filing metadata
- accession: 0001104659-26-076400
- form_type: 8-K
- ticker: FISN
- cik: 0001918102
- company_name: DEEP FISSION, INC.
- filed_at: 2026-06-22T20:20:56+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1918102/000110465926076400/0001104659-26-076400-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1918102/000110465926076400/tm2618457d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-26-076400
- JSON: https://secwatch.observer/filing/0001104659-26-076400.json
- Plain text: https://secwatch.observer/filing/0001104659-26-076400.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.