---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-26-067517"
form_type: "8-K"
ticker: "CLIR"
cik: "0001434524"
company_name: "ClearSign Technologies Corp"
filed_at: "2026-05-28T20:19:02+00:00"
generated_at: "2026-05-28T20:23:14.417819+00:00"
event_type: "regulatory"
sentiment: "neutral"
materiality_score: 0.3
calibrated_materiality_score: 0.3
confidence: "high"
source: SEC EDGAR
---

# ClearSign Technologies suspends ATM prospectus supplement for $10.39 million common stock offering; no shares sold

## Summary
- On May 26, 2026, ClearSign notified H.C. Wainwright of suspension and termination of the ATM prospectus supplement filed July 17, 2025.
- The ATM program allowed sale of up to $10.39 million in common stock, but no shares were sold before suspension.
- The ATM Agreement remains in effect, but no sales will occur until a new prospectus supplement is filed.
- Termination relates to shelf registration statement Form S-3 (File No. 333-288736) effective July 28, 2025.

## SEC filing metadata
- accession: 0001104659-26-067517
- form_type: 8-K
- ticker: CLIR
- cik: 0001434524
- company_name: ClearSign Technologies Corp
- filed_at: 2026-05-28T20:19:02+00:00
- event_type: regulatory
- sentiment: neutral
- materiality_score: 0.3
- calibrated_materiality_score: 0.3
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1434524/000110465926067517/0001104659-26-067517-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1434524/000110465926067517/tm2615697d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-26-067517
- JSON: https://secwatch.observer/filing/0001104659-26-067517.json
- Plain text: https://secwatch.observer/filing/0001104659-26-067517.txt

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