Note 8 - Warrants

12 Months Ended

Dec. 31, 2020

Notes to Financial Statements

Warrants [Text Block]

8. Warrants

In March 2014, pursuant to a to a registered public offering and note conversion agreement with certain note holders, the Company issued warrants to purchase 6,910,283 shares of common stock at $4.75 per share. The warrants expired on March 20, 2021.

In May 2016, in connection with our WAVI credit facility, the Company issued a warrant to purchase 550,000 shares of common stock at $1.75 per share. The warrant was immediately exercisable and expires in May 2021.

On May 14, 2020, the Company entered into separate warrant exercise agreements with WAVI Holding AG and Taurus4757 GmbH pursuant to which the warrant holders immediately exercised their respective warrants via a “cashless” exercise as agreed to by the Company. As a result of the cashless exercise, the Company issued an aggregate of 2,747,970 shares of Company common stock upon cashless exercise of an aggregate of 3,871,405 warrants.

Additionally, during the year ended December 31, 2020, 8,500 warrants were exercised with a weighted average exercise price of $4.75, yielding proceeds of $40,000.

The following table summarizes warrant activity for the years ended December 31, 2020 and 2019:

	Year Ended December 31, 2020					Year Ended December 31, 2019
	Shares			Wtd. Avg. Exercise Price		Shares			Wtd. Avg. Exercise Price
Outstanding at beginning of year		3,959,005		$	4.33		4,080,005		$	4.35
Exercised		(3,879,905	)		4.33		(121,000	)		4.75
Outstanding and exercisable at end of year		79,100		$	4.75		3,959,005		$	4.33