A summary of warrant activity during the nine months ended September 30, 2020 is as follows:



Warrants outstanding, December 31, 2019	10,384,706
Issuances	1,631,794
Exercises	(10,238,889	)
Warrants outstanding, September 30, 2020	1,777,611

During the nine months ended September 30, 2020, the Company received net proceeds of $41.0 million from warrant exercises.

For warrants classified as a liability, the following is a summary of the periodic changes in their fair value during the nine months ended September 30, 2020:

Balance, December 31, 2019	$	10,000
Changes in fair value		—
Balance, September 30, 2020	$	10,000