WARRANTS

From time to time, we have issued warrants to purchase shares of common stock. These warrants have been issued in connection with the financing transactions and consulting services. Our warrants are subject to standard anti-dilution provisions applicable to shares of our common stock.

In January 2018, we entered into an agreement with our founders to exchange warrants to purchase an aggregate of 249,999 shares of our common stock, with an exercise price of $0.20 per share, for an amount of shares that would equal the number of shares they would have received if exercised under a cashless exercise. The effect of exchanging the warrants for shares of our common stock was considered a modification of the award which required us to record expense for the excess of the fair value of the common stock issued over the fair value of the exchanged warrants. On the date of the exchange the fair value of the warrants was determined to be $1.6 million and the fair value of the shares of common stock issued were $1.6 million. There was a difference in fair value of $2,000 which was recorded to sales, marketing and administration expenses during the three months ended March 31, 2018. No expense was recorded in the three months ended March 31, 2019.

A roll-forward of warrant share activity from January 1, 2018 to March 31, 2018 is shown in the following table:



	Issued and Outstanding Warrants as of January 1, 2018	Warrants Exercised/ Expired			Issued and Outstanding Warrants as of March 31, 2018
Bridge Warrants	249,999	(249,999	)	(1)	—
Consulting Warrants	12,223	—			12,223
Financing Warrants	62,530	—			62,530
Underwriting Warrants	310,500	—			310,500
IR Consulting Warrants	6,000	—			6,000
Private Placement Warrants - 2016	891,063	(15,000	)	(2)	876,063
Underwriting Warrants - Public Offering 2016	122,175	—			122,175
Private Placement Warrants - September 2017	1,976,919	—			1,976,919
Placement Agent Warrants	98,846	—			98,846
	3,730,255	(264,999	)		3,465,256

(1) During the three months ended March 31, 2018, there were 249,999 warrants that were exchanged for 242,913 shares of common stock in an exchange transaction where the warrant holders exchanged the warrants for the same number of shares they would have been entitled to in a cashless exercise.

(2) During the three months ended March 31, 2018, there were 15,000 warrants exercised for cash.

A roll-forward of warrant share activity from January 1, 2019 to March 31, 2019 is shown in the following table:



	Exercise Price	Expiration Date	Issued and Outstanding Warrants as of January 1, 2019	Warrants Exercised/ Expired			Issued and Outstanding Warrants as of March 31, 2019
Consulting Warrants	$0.01	6/17/2020	6,667	—			6,667
Financing Warrants	$3.35	6/17/2020	62,530	—			62,530
Underwriting Warrants	$7.50	5/28/2019	310,500	—			310,500
Private Placement Warrants - 2016	$2.86	4/25/2019	818,063	(140,000	)	(1)	678,063
Underwriting Warrants - Public Offering 2016	$4.25	9/9/2019	122,175	—			122,175
Private Placement Warrants - September 2017	$4.85	9/28/2020	1,966,319	—			1,966,319
Placement Agent Warrants	$4.85	9/28/2020	98,846	—			98,846
			3,385,100	(140,000	)		3,245,100


(1)	During the three months ended March 31, 2019, there were 140,000 warrants exercised for cash.