Note 9 - Warrants

9 Months Ended

Sep. 30, 2026

Notes to Financial Statements

Warrants Disclosure [Text Block]

9.      Warrants

On February 11, 2021, Fuel Tech entered into a securities purchase agreement to issue and sell, in a private placement, 2,500,000 warrants exercisable for a total of 2,500,000 shares of Common Stock with an exercise price of $5.10 per Warrant Share. In addition, the Company issued to the placement agent Warrants to purchase up to 350,000 shares of Common Stock at an exercise price of $6.45 per Warrant Share. These warrants expired on August 11, 2026, the five and one-half year anniversary of the effective date of the registration statement for the Warrant Shares, as set forth in the securities purchase agreement. The below table summarizes the Warrant Share activity for the nine months ended September 30, 2026:

	Warrant Shares
Outstanding on January 1, 2026		2,850,000
Granted		—
Exercised		—
Expired		(2,850,000	)
Outstanding as of September 30, 2026		—