Note 6 - Stockholders' Equity

6 Months Ended

Jun. 30, 2021

Notes to Financial Statements

Stockholders' Equity Note Disclosure [Text Block]

Note 6 — Stockholders’ Equity

Sales of Common Stock

On April 24, 2020, the Company filed a shelf registration statement on Form S-3 with the SEC. This shelf registration statement became effective on May 14, 2020 and allows the Company to sell up to $500,000 in securities, including common stock, preferred stock, depositary shares, purchase contracts, warrants, debt securities, and units, from time to time at prices and on terms to be determined at the time of sale.

On June 1, 2020, the Company issued 22,044 shares of common stock to the public at a purchase price of $4.50 per share and pre-funded warrants to purchase 3,511 shares of common stock at a purchase of $4.49 per pre-funded warrant, for total net proceeds to the Company of $108,096 million after deducting underwriting discounts and commissions and other offering expenses. Each pre-funded warrant is exercisable, subject to conditions in the warrant agreement, into one share of common stock at an exercise price of $0.01 per share. All warrants issued in this offering remain outstanding at June 30, 2021.

On March 1, 2021, the Company filed an automatic shelf registration statement on Form S-3 with the SEC. This shelf registration statement became effective automatically upon filing and allows the Company to sell an indeterminate number of securities, including common stock, preferred stock, depositary shares, purchase contracts, warrants, debt securities, and units, from time to time at prices and on terms to be determined at the time of sale.