CLIR on Nasdaq

ClearSign Combustion

Logo: ClearSign Combustion, Public domain, via Wikimedia Commons4

American technology company

ClearSign Technologies Corporation (ClearSign) is a United States-based company that develops emission-control technology.3 From Wikipedia, CC BY-SA 4.0

Price unavailable

Last updated Oct 19, 2026.

Overview

2008Founded1

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  • TickerCLIR on Nasdaq1
  • IndustryIndustrial Instruments For Measurement, Display, and Control1
  • HeadquartersSeattle1
  • Websiteclearsign.com
  • Incorporated inDE5
  • Business address8023 E. 63Rd Place, Suite 101, Tulsa, Ok 741335
  • Filer categoryNon-accelerated filer, Smaller reporting company5
  • Legal formCorporation
ClearSignHQ
Photo: LavaBaron, CC0, via Wikimedia Commons7

ClearSign Technologies Corporation (ClearSign) is a United States-based company that develops emission-control technology.3

Financials

From the company’s reports to the SEC. Every number links to the filing it came from.

Key numbers, fiscal 2025

27.2%Gross margin8
-127.5%Operating margin8
-105.0%Net margin8
45.6%Revenue growth, 20258
-57.7%Return on equity8
-$4.7MFree cash flow8

Where the money goes

Where each dollar of revenue went, fiscal 2025

  • Cost of revenue73¢$3.8M
  • Research and development27¢$1.4M

Out of $5.2M in revenue.8 The company lost money this year.

Financial statements

Revenue9101112138$5.2M in 2025
0$2.0M$4.0M$6.0M2019: $0$020192020: $0$020202021: $607.0K$607.0K20212022: $374.0K$374.0K2022−38%2023: $2.4M$2.4M2023+543%2024: $3.6M$3.6M2024+50%2025: $5.2M$5.2M2025+46%
Gross profit9101112138$1.4M in 2025
-$500.0K0$500.0K$1.0M$1.5M2019: -$1.0K-$1.0K20192020: -$279.0K-$279.0K2020+27800%2021: -$452.0K-$452.0K2021+62%2022: $116.0K$116.0K20222023: $817.0K$817.0K2023+604%2024: $1.1M$1.1M2024+37%2025: $1.4M$1.4M2025+27%
Operating income9101112138-$6.7M in 2025−22% since 2019
-$10.0M-$7.5M-$5.0M-$2.5M02019: -$8.6M-$8.6M20192020: -$6.9M-$6.9M2020−19%2021: -$8.1M-$8.1M2021+17%2022: -$6.1M-$6.1M2022−25%2023: -$6.0M-$6.0M2023−2%2024: -$6.5M-$6.5M2024+8%2025: -$6.7M-$6.7M2025+3%
Net income9101112138-$5.5M in 2025−35% since 2019
-$10.0M-$7.5M-$5.0M-$2.5M02019: -$8.5M-$8.5M20192020: -$6.9M-$6.9M2020−19%2021: -$7.9M-$7.9M2021+15%2022: -$5.8M-$5.8M2022−27%2023: -$5.2M-$5.2M2023−10%2024: -$5.3M-$5.3M2024+2%2025: -$5.5M-$5.5M2025+4%

Every line of the income statement as filed: the last 2 fiscal years (annual) or 8 quarters (quarterly), latest first.8

Period ending2025-12-312024-12-31
Revenues$5.2M$3.6M
Cost of goods sold$3.8M$2.5M
Gross profit$1.4M$1.1M
Research and development$1.4M$1.5M
General and administrative$6.7M$6.1M
Total operating expenses$8.1M$7.6M
Loss from operations-$6.7M-$6.5M
Interest income$439.0K$516.0K
Government assistance$736.0K$664.0K
Other income, net$9.0K
Total other income, net$1.2M$1.2M
Net loss-$5.5M-$5.3M
Net loss per share - basic (in dollar per share)-$0.99-$1.08
Net loss per share - fully diluted (in dollar per share)-$0.99-$1.08
Weighted average number of shares outstanding - basic (in shares)5.6M shares4.9M shares
Weighted average number of shares outstanding - fully diluted (in shares)5.6M shares4.9M shares
Net loss-$5.5M-$5.3M
Foreign-exchange translation adjustments$1.0K-$4.0K
Comprehensive loss-$5.5M-$5.3M

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The story

ClearSign was formed in Seattle, Washington in 2008. Its first chief executive officer was Richard Rutkowski, who also became chairman of the board of directors. Rutkowski was a co-founder of projection technology company Microvision and nanotechnology company Lumera.

In 2012 ClearSign held an initial public offering which, according to the company, raised $13.8 million. ClearSign chose to delay adopting accounting standards required of publicly traded companies under the Sarbanes-Oxley Act, taking advantage of exemptions in the JOBS Act designed to make it cheaper for development-stage companies to raise capital. It is believed ClearSign may have been the first company in the U.S. to do so.

In December 2014, Rutkowski resigned as CEO. He was replaced by board member Stephen Pirnat. The following September, the company was named "Technology Company of the Year" by Petroleum Economist.

On November 12, 2019, ClearSign Combustion Corporation (Nasdaq: CLIR) (“ClearSign” or the “Company”), announced that the company has changed its name to ClearSign Technologies Corporation. The company's ticker “CLIR” will remain the same.

As of September 2024, ClearSign Technologies held US$14 million in cash and had no debt. Over the preceding year, the company reported a cash burn of US$5.7 million, indicating a projected cash runway of approximately 2.5 years from that date. During the same period, ClearSign increased its cash burn by 115%, reflecting a significant rise in investment activity. This coincided with a 263% increase in revenue over the year.

From Wikipedia’s article on ClearSign Technologies, shared under CC BY-SA 4.0.6

Leadership

Who has led ClearSign Combustion, and when. Pick a name to see everywhere that person has worked.

Board members and other officers (27)

Named in SEC Form D filings

People the company listed in its private-offering notices.

  • DirectorTodd Gil Silva named Jul 31, 202649
  • DirectorCatharine S. de Lacy named May 8, 2024 to Jul 9, 202450
  • DirectorRobert T. Hoffman Sr. named May 8, 202451

Products and brands

ClearSign develops technology intended to increase energy efficiency and emissions standards of combustion systems, primarily industrial and commercial boilers and furnaces. Its products include Duplex Burner Architecture, which the company says reduces combustion burner flame length by more than 80-percent, in turn increasing thermal capacity and reducing operating costs. Duplex Burner Architecture won the "New Technology Development of the Year Award" at the 2014 West Coast Oil & Gas Awards. The company's other major product is Electrodynamic Combustion Control, which uses computer-controlled electric fields to control the flame shape in boilers, kilns, and furnaces, preventing pollution from forming.

From Wikipedia’s article on ClearSign Technologies, shared under CC BY-SA 4.0.6

Former names

  • CLEARSIGN COMBUSTION CORPMay 5, 2008 to Oct 31, 20195

Timeline

  1. Feb 14, 2020New chief executive Colin James Deller becomes CEO16
  2. Feb 5, 2015New chief executive Stephen E. Pirnat becomes CEO17
  3. Apr 24, 2012New chief executive Richard F. Rutkowski becomes CEO18
  4. 2008Founded Founded1

Filings

291 filings to the SEC since October 2021: 8 annual reports, 17 quarterly reports, 71 major events, 115 insider forms, 6 large holders, 3 private raises, 71 other. The latest 20:

  1. Oct 2, 20264 OWNERSHIP DOCUMENT EDGAR
  2. Oct 2, 20264 OWNERSHIP DOCUMENT EDGAR
  3. Oct 2, 20264 OWNERSHIP DOCUMENT EDGAR
  4. Oct 2, 20264 OWNERSHIP DOCUMENT EDGAR
  5. Sep 14, 20268-K EDGAR
  6. Aug 20, 20268-K EDGAR
  7. Aug 14, 202610-Q EDGAR
  8. Aug 11, 20263 OWNERSHIP DOCUMENT EDGAR
  9. Aug 11, 20268-K EDGAR
  10. Jul 31, 2026D EDGAR
  11. Jul 24, 2026SCHEDULE 13G/A EDGAR
  12. Jul 24, 20264 PRIMARY DOCUMENT EDGAR
  13. Jul 23, 20268-K EDGAR
  14. Jul 6, 2026S-8 EDGAR
  15. Jul 6, 20268-K EDGAR
  16. Jul 6, 2026424B5 EDGAR
  17. Jul 2, 20264 OWNERSHIP DOCUMENT EDGAR
  18. Jul 2, 20264 OWNERSHIP DOCUMENT EDGAR
  19. Jul 2, 20264 OWNERSHIP DOCUMENT EDGAR
  20. Jun 18, 20268-K EDGAR

The 291 filings since October 2021 can be filtered by form type and year here when JavaScript is on.

Every filing from the last five years, summarized. The full record is on SEC EDGAR.

Insider trades

7 open-market trades by officers, directors and large owners since October 2021: 7 buys and 0 sales. Grants, option exercises and gifts are left out.

DateWhoTradeSharesPriceValueFiling
Jul 22, 2026PASQUESI JOHN M10% ownerBuy500,000$3.54$1.8MForm 4
Apr 23, 2026Silva Gil ToddDirectorBuy2,000$5.29$10.6KForm 4
Mar 17, 2026Silva Gil ToddDirectorBuy2,000$4.20$8.4KForm 4
Mar 16, 2026Silva Gil ToddDirectorBuy2,000$4.36$8.7KForm 4
Jun 24, 2024Princeton Opportunity Management LLC10% ownerBuy3,350,000$0.91$3.0MForm 4
Jul 8, 2022clirSPV LLC10% ownerBuy1,591,594$1.11$1.8MForm 4
Jun 14, 2022Pate Bruce AlanDirectorBuy45,000$1.12$50.4KForm 4

From Forms 4 filed with the SEC.

Major holders

Investors who own more than 5% of the shares must tell the SEC: a 13D if they may seek to influence the company, a 13G if they hold passively.

Money raised

Private offerings the company reported to the SEC on Form D.

  1. Jul 22, 2026Raised $1.8 million in a private offering of equity Form D: 1 investor so far Form D
  2. Jun 24, 2024Raised $4.3 million in a private offering of equity Form D: $11.7 million offered in all Form D
  3. Apr 23, 2024Raised $5 million in a private offering of equity Form D: $14.4 million offered in all Form D

Held by these funds

The largest holders among investment managers' 13F reports for the quarter ending Jun 30, 2026. Change is in shares since the quarter before.

FundSharesValueShare of the fundChange
Vanguard Capital Management LLC105,429$386.9K0.0%No change
Simon Quick Advisors, LLC60,314$221.4K0.0%No change
Geode Capital Management, LLC51,457$188.9K0.0%−6,226
Beacon Pointe Advisors, LLC27,173$99.7K0.0%No change
Vanguard Fiduciary Trust Co23,460$86.1K0.0%No change
HighTower Advisors, LLC22,662$83.2K0.0%+9,982
Citadel Advisors LLC20,565$75.5K0.0%New
BlackRock, Inc.19,503$71.6K0.0%No change
DDD Partners, LLC12,000$44.0K0.0%No change
Northern Trust Corp10,080$37.0K0.0%New
Rockefeller Capital Management L.P.8,120$29.8K0.0%No change
Northwestern Mutual Wealth Management Co7,172$26.3K0.0%No change
Wells Fargo & Company/mn2,125$7.8K0.0%No change
Gleason Group, Inc.1,802$6.6K0.0%No change
Tower Research Capital LLC (TRC)1,518$5.6K0.0%+473
Vanguard Global Advisers, LLC1,350$5.0K0.0%No change
Royal Bank Of Canada684$3.0K0.0%New
Integrated Wealth Concepts LLC687$2.5K0.0%New
Deutsche Bank Ag\400$1.5K0.0%No change
UBS Group AG100$3670.0%New
Cambridge Investment Research Advisors, Inc.88,600$3260.0%+44,300
Barclays PLC33$1210.0%New
SBI Securities Co., Ltd.12$440.0%+1
Group One Trading LLC9$330.0%No change

13F reports cover disclosed long positions in U.S. stocks only.

Sources

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