The shares of common stock were sold under the Company’s shelf registration statement on Form S-3 originally filed on July 6, 2018 and declared effective July 23, 2019 (the “2019 Shelf”) through May 27, 2020.
On May 18, 2020, the Company filed a new shelf registration statement on Form S-3, which was declared effective on May 26, 2020 (the "2020 Shelf"). In connection with the 2020 Shelf, the Company entered into an At Market Issuance Sales Agreement ("2020 Common ATM"), with Cantor Fitzgerald & Co., Oppenheimer & Co., Inc., H.C. Wainwright & Co. Inc., B. Riley and Dawson James Securities, Inc., as selling agents, governing potential sales of the Company's common stock. ATM sales commencing on June 1, 2020 were made under the 2020 Shelf.
For the nine-month period ended September 30, 2020, the Company issued approximately 16.4 million shares of common stock at an average price of $2.74 per share for gross proceeds of $44.8 million. In connection with these sales, the Company paid aggregate fees of approximately $1.6 million. Approximately $29.5 million of securities remain available for sale under the 2020 Shelf at September 30, 2020.
Mustang At-the-Market Offering
On July 13, 2018, Mustang filed a shelf registration statement No. 333-226175 on Form S-3, as amended on July 20, 2018 (the "2018 Mustang S-3"), which was declared effective in August 2018. Under the 2018 Mustang S-3, Mustang may sell up to a total of $75.0 million of its securities. In connection with the 2018 Mustang S-3, Mustang entered into an At-the-Market Issuance Sales Agreement (the "Mustang ATM") with B. Riley FBR, Inc., Cantor Fitzgerald & Co., National Securities Corporation, and Oppenheimer & Co. Inc. (each an "Agent" and collectively, the "Agents"), relating to the sale of shares of common stock. Under the Mustang ATM, Mustang pays the Agents a commission rate of up to 3.0% of the gross proceeds from the sale of any shares of Mustang common stock.
On August 16, 2019, Mustang filed a shelf registration statement No. 333-233350 on Form S-3, (the "2019 Mustang S-3"), which was declared effective on September 30, 2019. Under the 2019 Mustang S-3, Mustang may sell up to a total of $75.0 million of its securities. On July 20, 2020, Mustang entered into Amendment No. 1 to the Mustang ATM with the Agents to reflect the new registration statement.
During the nine months ended September 30, 2020, Mustang issued approximately 7.2 million shares of common stock at an average price of $3.56 per share for gross proceeds of $25.6 million under the Mustang ATM. In connection with these sales, Mustang paid aggregate fees of approximately $0.5 million for net proceeds of approximately $25.1 million. During the nine months ended September 30, 2019, Mustang issued approximately 3.5 million shares of common stock at an average price of $6.42 per share for gross proceeds of $22.5 million under the Mustang ATM. In connection with these sales, Mustang paid aggregate fees of approximately $0.5 million for net proceeds of approximately $22.0 million. Pursuant to the Founders Agreement, Mustang issued 117,405 shares of common stock to Fortress at a weighted average price of $3.56 per share for the nine months ended September 30, 2020 for the Mustang ATM offering noted above. During the nine months ended September 30, 2019, Mustang issued 87,656 shares of common stock to Fortress at a weighted average price of $6.42 per share in connection with the Mustang ATM.
Approximately $32.6 million of the Mustang shelf remains available for sale under the 2019 Mustang S-3, following the offerings noted above. As of September 30, 2020, the 2018 Mustang S-3 is no longer available for sales of securities.
Checkpoint At-the-Market Offering
Under the Checkpoint S-3, Checkpoint may sell up to a total of $100 million of its securities. In connection with the Checkpoint S-3, Checkpoint entered into an At-the-Market Issuance Sales Agreement (the "Checkpoint ATM") with Cantor Fitzgerald & Co., Ladenburg Thalmann & Co. Inc. and H.C. Wainwright & Co., LLC (each a "Checkpoint Agent" and collectively, the "Checkpoint Agents"), relating to the sale of shares of common stock. Under the Checkpoint ATM, Checkpoint pays the Checkpoint Agents a commission rate of up to 3.0% of the gross proceeds from the sale of any shares of Checkpoint common stock.
During the nine months ended September 30, 2020, Checkpoint sold a total of 3,614,344 shares of common stock under the Checkpoint ATM for aggregate total gross proceeds of approximately $8.7 million at an average selling price of $2.40 per share, resulting in net proceeds of approximately $8.4 million after deducting commissions and other transaction costs.