---
schema_version: "secwatch.filing_event.v1"
accession: "0001819438-26-000053"
form_type: "8-K"
ticker: "GWH"
cik: "0001819438"
company_name: "ESS Tech, Inc."
filed_at: "2026-06-23T12:36:41+00:00"
generated_at: "2026-06-23T12:40:14.164334+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# ESS accelerates sodium-ion BESS, reports $13.6M cash, streamlines Wilsonville ops

## Summary
- Cash, equivalents and short-term investments of $13.6M as of May 31, 2026 (unaudited).
- Citing strong early demand, ESS is accelerating sodium-ion BESS development; identifies ~$1B in early-stage opportunities.
- Streamlining Wilsonville operations, reducing expenses and cash burn to reallocate capital to sodium-ion and related solutions.
- Will continue iron flow battery development for long-duration, but shifts primary focus to sodium-ion for near-term revenue.
- Updated risk factors reflect NYSE minimum share price non-compliance (previously reported June 15, 2026) and the strategic pivot.

## SEC filing metadata
- accession: 0001819438-26-000053
- form_type: 8-K
- ticker: GWH
- cik: 0001819438
- company_name: ESS Tech, Inc.
- filed_at: 2026-06-23T12:36:41+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 2.02, 8.01, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1819438/000181943826000053/0001819438-26-000053-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1819438/000181943826000053/wk-20260623.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001819438-26-000053
- JSON: https://secwatch.observer/filing/0001819438-26-000053.json
- Plain text: https://secwatch.observer/filing/0001819438-26-000053.txt

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