ClearSign Technologies Corp — Director's Dealing 2026

Feb 25, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ClearSign Technologies Corp (CLIR)
CIK: 0001434524
Period of Report: 2026-02-20

Reporting Person: Hinds Brent (Chief Financial Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2026-02-20	Common Stock	M	9315	—	Acquired	133571	Direct
2026-02-20	Common Stock	F	3413	$0.5949	Disposed	130158	Direct
2026-02-22	Common Stock	M	7547	—	Acquired	137705	Direct
2026-02-22	Common Stock	F	2765	$0.5949	Disposed	134940	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2026-02-20	Restricted Stock Unit	$	M	9315	Disposed		Common Stock (9315)	Direct
2026-02-22	Restricted Stock Unit	$	M	7547	Disposed		Common Stock (7547)	Direct

Footnotes

F1: Reflects the vesting of 9,315 restricted stock units ("RSUs") out of the 27,946 RSUs granted to the reporting person on February 20, 2025, into an equal number of shares of the Company's common stock, without the payment of any consideration, pursuant to the Company's 2021 Equity Incentive Plan.

F2: Represents the payment of the reporting person's tax liability by withholding shares in connection with the vesting of 9,315 RSUs on February 20, 2026, and calculated based on the closing price of the Company's common stock, as reported on the Nasdaq Stock Market, on February 20, 2026, of $0.5949.

F3: Reflects the vesting of 7,547 RSUs out of the 22,641 RSUs granted to the reporting person on February 22, 2024, into an equal number of shares of the Company's common stock, without the payment of any consideration, pursuant to the Company's 2021 Equity Incentive Plan.

F4: Represents the payment of the reporting person's tax liability by withholding shares in connection with the vesting of 7,547 RSUs on February 22, 2026, and calculated based on the closing price of the Company's common stock, as reported on the Nasdaq Stock Market, on February 20, 2026, of $0.5949 (as February 22, 2026 fell on a weekend).

F5: On February 20, 2025, the reporting person was granted 27,946 RSUs as a one-time bonus for services as an executive officer for the year ended December 31, 2024, and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F6: The RSUs granted on February 20, 2025, vest in three equal installments that commenced on February 20, 2026.

F7: On February 22, 2024, the reporting person was granted 22,641 RSUs as a one-time bonus for services as an executive officer for the year ended December 31, 2023, and each RSU represents a right to receive one share of common stock or the cash equivalent thereof.

F8: The RSUs granted on February 22, 2024, vest in three equal installments that commenced on February 22, 2025.