Note 3 - Basis of Presentation and Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2020

Notes Tables

Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]

	September 30, 2020
	Level 1		Level 2		Level 3
Assets
Cash equivalents	$	21,570,461	$	—	$	—

	December 31, 2019
	Level 1		Level 2		Level 3
Assets
Cash equivalents	$	14,006,193	$	—	$	—

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	As of September 30,
	2020		2019
Common stock warrants		9,100,112		3,469,825
Stock options		2,040,204		309,276
Unvested restricted stock awards		153,000		—
		11,293,316		3,779,101