Note 12 - Common Stock Warrants

9 Months Ended

Sep. 30, 2025

Notes to Financial Statements

Warrants and Rights Disclosure [Text Block]

12. Common Stock Warrants

Historically, the Company has entered into warrant agreements in connection with certain consulting agreements and equity offerings. In August 2023, the Company implemented a 1-for-100 reverse stock split pursuant to which, per the terms of the agreements, the number of shares of common stock issuable upon exercise of each of the warrants outstanding at that time was reduced by dividing the quantity outstanding by 100 and the exercise price of each such warrant was multiplied by 100. No other terms of the warrants were changed as a result of the reverse stock split. Additionally, in March 2025, the Company implemented a 1-for-17 reverse stock split pursuant to which, per the terms of the agreements, the number of shares of common stock issuable upon exercise of each of the warrants outstanding at that time was reduced by dividing the quantity outstanding by 17 and the exercise price of each such warrant was multiplied by 17. No other terms of the warrants were changed as a result of the reverse stock split.

In July 2021, the Company entered into a consulting agreement, pursuant to which warrants to purchase 30 shares of common stock were granted and warrants to purchase an additional 30 shares of common stock were granted in November 2021. The warrants are exercisable upon issuance, have an exercise price of $1,768.00 per share and have a term of five years. The consulting agreement was effective as of February 2021, had an initial monthly fee of $5 thousand and a term of two years. The agreement was amended in May of 2022 to increase the monthly payment to $7.5 thousand. Currently, the agreement is automatically renewing on a month-to-month basis until terminated by either party. The warrant issuances are indexed to, and settled in, the Company’s own common stock and were classified within stockholders’ equity.

In November 2021, the Company issued warrants to purchase 102 shares of common stock to designees of ThinkEquity LLC (“ThinkEquity”), the underwriter of the Company’s initial public offering. The warrants may be exercised at any time on or after May 9, 2022, have an exercise price of $10,625.00 per share and have a term of five years. The warrant issuances are indexed to and settled in the Company’s own common stock and were classified within stockholders’ equity.

In February 2023, the Company issued warrants to purchase 589 shares of common stock to designees of ThinkEquity, the underwriter of the underwritten public offering of 11,765 shares of Company common stock that closed in February 2023. The designees paid an aggregate of $0.1 thousand for the warrants. The warrants may be exercised at any time on or after August 7, 2023, have an exercise price of $531.25 per share, and have a term of four years commencing 180 days following the commencement of sales in the offering. The warrant issuances were indexed to and settled in the Company’s own stock and were classified within stockholders’ equity.

In July and August 2023, the Company issued warrants to purchase an aggregate of 2,805 shares of common stock to Maxim, the placement agent for each of the three public offerings of the Company’s common stock completed during the period. The warrants are exercisable at any time beginning six months after the close of the applicable equity offering and expire five years from the commencement of sales under the applicable offering. Of the warrants issued in the offerings, 765 are exercisable beginning on January 11, 2024 at a price of $113.20 per share; 1,206 are exercisable beginning on January 19, 2024 at a price of $81.60 per share; and 781 are exercisable beginning on February 9, 2024 at a price of $83.64 per share.

In May 2024, in connection with the sale of 277,059 shares of common stock, the Company issued Series A Warrants to purchase an aggregate of 277,059 shares of common stock and Series B Warrants to purchase an aggregate of 415,589 shares of common stock to the purchasers of the stock. The warrants are exercisable upon issuance and have an exercise price of $14.45 per share. During the six months ended June 30, 2025, a total of 7,524 Series A Warrants were exercised for total proceeds of $109 thousand. All remaining outstanding Series A Warrants expired on May 13, 2025 and the Series B Warrants expire on May 14, 2029. Additionally, the Company issued warrants to purchase 11,083 shares of common stock to Maxim, the placement agent for the public offering of the Company’s securities. The placement agent warrants are exercisable at any time beginning six months after the closing date of the equity offering and expire five years from the from the commencement of sales under the offering.

The Company estimated the value of the warrants issued to the placement agent in May 2024 using the Black-Scholes options valuation model. The fair value of the warrants issued in February 2023 was $195 thousand and was recognized as issuance costs of the common stock issued in the underwritten public offering and was classified within stockholders’ equity. The fair value of the warrants issued in July and August 2023 totaled $168 thousand and was recognized as issuance costs of the common stock issued in the three offerings during the period and was classified within stockholders’ equity. The fair value of the warrants issued in May 2024 was $70 thousand and was recognized as issuance costs of the common stock issued in the public offering and was classified within stockholders’ equity as additional paid in capital.

In June 2025, in connection with the Initial Tranche Closing, the Company issued Investor Warrants to purchase 61,287 shares of common stock. The Investor Warrants are exercisable upon issuance, had an initial exercise price of $3.85 per share and expire on June 25, 2030. On August 21, 2025, in connection with closing of the Third Tranche and pursuant to the Investor Warrants, the exercise price of the Investor Warrants issued in the Initial Tranche was reduced to $3.372 per share. On September 26, 2025, in connection with closing of the Fourth Tranche and pursuant to the Investor Warrants, the exercise price of the Investor Warrants issued in the Initial Tranche was further reduced to $3.04 per share. Additionally, the Company issued warrants to purchase 10,000 shares of common stock to designees of Craft, the placement agent in connection with the Tranched Financing, as partial consideration for services rendered by Craft in connection therewith. The placement agent warrants are exercisable upon issuance, have an exercise price of $4.20 per share and expire on June 25, 2029.

The Company estimated the value of the placement agent warrants issued to the Craft designees using the Black-Scholes options valuation model. The fair value was $36 thousand and was recognized as issuance costs of the Series B Preferred Stock issued in the offering and was classified within stockholders’ equity as additional paid in capital.

In July 2025, in connection with the Second Tranche Closing, the Company issued Investor Warrants to purchase 64,065 shares of common stock. The Investor Warrants are exercisable upon issuance, had an initial exercise price of $3.996 per share and expire on July 31, 2030. On August 21, 2025, in connection with closing of the Third Tranche and pursuant to the Investor Warrants, the exercise price of the Investor Warrants issued in the Initial Tranche was reduced to $3.372 per share. On September 26, 2025, in connection with closing of the Fourth Tranche and pursuant to the Investor Warrants, the exercise price of the Investor Warrants issued in the Initial Tranche was further reduced to $3.04 per share. Additionally, the Company issued warrants to purchase 11,068 shares of common stock to designees of Craft, the placement agent in connection with the Tranched Financing, as partial consideration for services rendered by Craft in connection therewith. The placement agent warrants are exercisable upon issuance, have an exercise price of $3.795 per share and expire on July 31, 2029.

The Company estimated the value of the placement agent warrants issued to the Craft designees using the Black-Scholes options valuation model. The fair value was $31 thousand and was recognized as issuance costs of the Series B Preferred Stock issued in the offering and was classified within stockholders’ equity as additional paid in capital.

In August 2025, in connection with the Third Tranche Closing, the Company issued Investor Warrants to purchase 188,842 shares of common stock. The Investor Warrants are exercisable upon issuance, had an initial exercise price of $3.372 per share and expire on August 21, 2030. On September 26, 2025, in connection with closing of the Fourth Tranche and pursuant to the Investor Warrants, the exercise price of the Investor Warrants issued in the Initial Tranche was further reduced to $3.04 per share. Additionally, the Company issued warrants to purchase 29,830 shares of common stock to designees of Craft, the placement agent in connection with the Tranched Financing, as partial consideration for services rendered by Craft in connection therewith. The placement agent warrants are exercisable upon issuance, have an exercise price of $3.52 per share and expire on August 21, 2029.

The Company estimated the value of the placement agent warrants issued to the Craft designees using the Black-Scholes options valuation model. The fair value was $77 thousand and was recognized as issuance costs of the Series B Preferred Stock issued in the offering and was classified within stockholders’ equity as additional paid in capital.

In August 2025, the Company issued warrants to purchase an aggregate of 32,500 shares of common stock to two individuals in exchange for investor relations services provided.  The warrants are exercisable upon issuance, have an exercise price of $3.64 per share and expire on August 11, 2029.  The Company estimated the value of the warrants issued to the individuals using the Black-Scholes options valuation model. The fair value was $94 thousand and was classified within stockholders’ equity as additional paid in capital.

In September 2025, in connection with the Fourth Tranche Closing, the Company issued to the Investor warrants to purchase 195,793 shares of common stock. The warrants are exercisable upon issuance, have an initial exercise price of $3.04 per share and expire on September 26, 2030. Additionally, the Company issued warrants to purchase 32,249 shares of common stock to designees of Craft, the placement agent in connection with the Tranched Financing, as partial consideration for services rendered by Craft in connection therewith. The placement agent warrants are exercisable upon issuance, have an exercise price of $3.256 per share and expire on September 26, 2029.

The Company estimated the value of the placement agent warrants issued to the Craft designees using the Black-Scholes options valuation model. The fair value was $78 thousand and was recognized as issuance costs of the Series B Preferred Stock issued in the offering and was classified within stockholders’ equity as additional paid in capital.

The fair value of the warrants issued to placement agents in 2025 and 2024 was estimated on the date of grant using the following assumptions:

	2025						2024
	Minimum			Maximum			Minimum			Maximum
Expected life (in years)		4.0			5.0			5.0			5.0
Expected volatility		126.3	%		187.8	%		118.6	%		118.6	%
Risk-free interest rate		3.71	%		3.96	%		4.50	%		4.50	%
Dividend yield		0	%		0	%		0	%		0	%

A summary of the Company’s outstanding warrants as of September 30, 2025 is as follows:

Class of Shares	Number of Warrant Shares		Exercise Price of Warrants		Expiration Date of Warrants
Common Stock		30	$	1,768.00	July 1, 2026
Common Stock		30	$	1,768.00	November 15, 2026
Common Stock		102	$	10,625.00	November 10, 2026
Common Stock		589	$	531.25	August 9, 2027
Common Stock		765	$	112.20	July 10, 2028
Common Stock		1,206	$	81.60	July 14, 2028
Common Stock		781	$	83.64	August 4, 2028
Common Stock		11,083	$	15.90	May 9, 2029
Common Stock		415,589	$	14.45	May 14, 2029
Common Stock		61,287	$	3.04	June 25, 2030
Common Stock		10,000	$	4.20	June 25, 2029
Common Stock		64,065	$	3.04	July 31, 2030
Common Stock		11,068	$	3.80	July 31, 2029
Common Stock		32,500	$	3.64	August 11, 2029
Common Stock		188,842	$	3.04	August 21, 2030
Common Stock		29,830	$	3.52	August 21, 2029
Common Stock		195,793	$	3.04	September 26, 2030
Common Stock		32,249	$	3.26	September 26, 2029
Total		1,055,809

During the nine months ended September 30, 2025, a total of 7,524 Series A Warrants were exercised for total proceeds of $109 thousand. There were no warrant exercises in the nine months ended September 30, 2024.