Deep Fission (FISN)
Develops borehole-installed nuclear reactors for reliable low-carbon power.
Something off on this page? Send us feedback.
Develops a borehole-installed pressurized-water reactor for reliable, low-carbon power, with planned delivery, project-development, licensing, and service revenue. The business remains pre-revenue, while commercial deployment depends on drilling and emplacement proof, NRC licensing, fuel, suitable sites, and grid access.
Develops the Gravity Nuclear Reactor, a small pressurized-water reactor designed for a water-filled, lined borehole about one mile underground. A factory-assembled module transfers heat through closed loops to surface equipment for electricity conversion. The initial focus is reliable, low-carbon baseload power for data centers, industrial users, utilities, and government or defense installations in the United States.
Builds around established PWR technology and conventional low-enriched uranium, with drilling, underground emplacement, integration, and proof-of-concept installation central to the program. Planned revenue sources include reactor delivery, project development, technology licensing, and operations and maintenance, but no revenue has begun. Commercial deployment requires NRC licensing; DOE authorization governs a separate test-reactor path.
Company facts
No analyst consensus on record.
EPSReportedEstimate
RevenueReportedEstimate
Balance sheet, Jun 30, 2026Cash & short-term investments $93.0M · Total debt $56.0K · Total assets $107.3M · Shareholders' equity $98.8M
- Revenue
- $0
- Operating income
- −$31.6M
- Net income
- −$31.0M
No dividends on record.
| Institutions | 3.90% | 2.30M shares | |
|---|---|---|---|
| 22 holders · as of Jun 30, 2026 | |||
| Other | 96.10% | 56.61M shares | |
| remainder | |||
58.91M company shares as of Sep 22, 2026 · institutions as of Jun 30, 2026 · holders as of their latest filing
Top shareholders13F · 13D/G · Form 4
| Holder | Stake | Shares | Date |
|---|---|---|---|
Blue Owl Capital Holdings LPInstitution | 2.26% | 1.33M | as of Jun 30, 2026 |
Elevation Wealth Management LLCInstitution | 0.51% | 298,335 | as of Jun 30, 2026 |
UBS Group AGInstitution | 0.34% | 198,497 | as of Jun 30, 2026 |
Consolidated Press International Holdings LtdInstitution | 0.23% | 133,333 | as of Jun 30, 2026 |
Citadel Advisors LLCInstitution | 0.19% | 110,000 | as of Jun 30, 2026 |
Insider tradesForm 4
Nothing filed in the last 12 months.
- Oklo
Data-center and industrial clean-power rival with Aurora reactors.
- NuScale Power
Closest water-cooled SMR rival for modular utility and industrial plants.
- X-energy
Data-center and industrial SMR rival with Xe-100 and an Amazon pipeline.
- GE Vernova
Large utility SMR contender through the BWRX-300 platform.
- Nano Nuclear Energy
Microreactor prospect for on-site AI data-center and defense power.
- BWX Technologies
Defense-focused transportable microreactor and nuclear-manufacturing rival.
CompareAfter hours
| Company | Price | Change | |||||
|---|---|---|---|---|---|---|---|
| Deep Fission | $8.12 | 0.00% | $471.8M | — | — | — | — |
| Oklo | $40.50 | +0.12% | $6.99B | — | — | 5,777.7 | — |
| NuScale Power | $8.92 | +0.39% | $2.62B | — | — | 245.5 | −99.1% |
| X-energy | $16.41 | +0.24% | $359.3M | — | — | — | — |
| GE Vernova | $951.24 | +0.08% | $252.01B | 27.2 | 46.1 | 6.1 | +21.9% |
| Nano Nuclear Energy | $17.38 | +0.40% | $918.2M | — | — | 4,290.0 | — |
| BWX Technologies | $144.60 | +0.11% | $13.51B | 38.0 | 28.9 | 3.8 | +18.0% |
| Median | 32.6 | 37.5 | 245.5 | +18.0% |