Key facts
- Fourth Power’s last known valuation is $100.0M (Sep 2025).
- It has raised $39.0M; the latest was Early Stage VC ($20.0M) in Sep 2025.
- Notable investors include DCVC, Breakthrough Energy, Munich Re Ventures, Black Venture Capital Consortium.
- Status: Privately Held (backing).
- ·The complete investor list — 4 names
- ·Watchlist + deal alerts for Fourth Power
- ·The full record, as it builds
Funding rounds
No funding rounds for Fourth Power are on record yet — either the company hasn't raised institutional capital, or the raise hasn't surfaced in our sources.
About Fourth Power
Developer of thermal battery storage designed to harness wasted wind and solar production to respond to grid needs with fossil fuels. The company's product provides storage to meet needs now and scale with renewable deployment and offers a modular storage system that grows with the grid, providing short-duration storage now and long-duration energy storage later as the transition to fully decarbonized infrastructure takes place, enabling clients to give grid operators complete control over how and when the stored energy is used.
- Sector
- Energy
- HQ
- Cambridge, MA, United States
- Founded
- 2021
- Employees
- 7
- Website
- gofourth.com/
- Ownership
- Privately Held (backing)
Fourth Power doesn't have a composite mark yet — a PA Mark is published once enough pricing inputs exist (trade prints, fund marks, round prices). The rest of the record below builds toward it.
Recorded secondary trades
No secondary trades in Fourth Power shares have been recorded yet. When a print lands — third-party, direct report, or platform — it appears here with structure, source, and price.
Institutional fund marks
No SEC-registered fund has reported a fair-value mark on Fourth Power in its N-PORT filings yet. We sweep new filings monthly.