Warrants

Warrants issued and outstanding at both September 30, 2018 and December 31, 2017 are as follows (in thousands, except share and per share data):



	Series	Date			Number of Shares Underlying Warrants	Price per Share		Fair Value at the Date of Issuance
Warrants to purchase	Series	Issuance	Expiration		Number of Shares Underlying Warrants	Price per Share		Fair Value at the Date of Issuance
Common stock		7/19/2013	7/22/2023	[a]	101,010	$	3.96	$	244
Common stock		11/26/2014	11/26/2024	[a]	21,928	$	3.42	$	47
Common stock		3/1/2017	3/1/2027	[a]	1,388	$	5.94	$	5
Total common stock warrants					124,326

Redeemable convertible preferred stock	Series 5	7/1/2012	7/25/2019	[b]	54,917	$	9.10	$	255
Redeemable convertible preferred stock	Series 5	7/19/2013	7/22/2023	[c]	21,989	$	9.10	$	122
Redeemable convertible preferred stock	Series 6	11/26/2014	11/26/2024	[c]	6,310	$	16.47	$	49
Redeemable convertible preferred stock	Series 6	10/20/2015	10/20/2025	[c]	39,339	$	16.47	$	396
Redeemable convertible preferred stock	Series 6	11/9/2015	11/9/2025	[c]	24,283	$	16.47	$	244
Redeemable convertible preferred stock	Series 7	12/22/2016	12/22/2026	[c]	9,712	$	10.03	$	45
Total redeemable convertible preferred stock warrants					156,550
Total outstanding common and redeemable convertible preferred stock warrants					280,876


[a]	Common stock warrants will remain outstanding until exercised by the holder.


[b]	These warrants will be net exercised immediately upon the closing of the Company’s IPO, or upon a corporate transaction as defined in the Note and Warrant Purchase Agreement dated July 25, 2012.


[c]	Convertible preferred stock warrants will remain outstanding until exercised by the holder and will convert to common stock warrants upon an IPO. The warrants will be exercisable for 10 years from the date of issuance.

In connection with previously issued debt, the Company issued 101,010 warrants to purchase common shares of the Company at an exercise price of $3.96 per share in July 2013. Additionally, the Company issued warrants to purchase an additional 21,928 shares of common stock at an exercise price of $3.42 per share in November 2014. The Company determined that its warrants to purchase shares of common stock meet the requirements for equity classification.

In conjunction with debt issued in July 2012, the Company issued warrants which became exercisable for an aggregate of 54,917 shares of Series 5 preferred stock of the Company at an exercise price of $9.10 per share.

In conjunction with debt issued in 2013 and 2014, the Company issued 21,989 warrants to purchase Series 5 redeemable convertible preferred stock of the Company at an exercise price of $9.10 per share. Subsequently, the Company issued additional warrants to purchase 6,310 shares of Series 6 redeemable convertible preferred stock at an exercise price of $16.47 per share.

In conjunction with the debt agreement with SVB and Oxford, or Term Loan agreement (refer to Note 6), the Company issued warrants to purchase 39,339 shares of Series 6 redeemable convertible preferred stock at an exercise price of $16.47 per share in October 2015 and additional 24,283 shares of Series 6 redeemable convertible preferred stock at an exercise price of $16.47 per share in November 2015.

In conjunction with the Term Loan agreement and its modification (refer to Note 6), the Company issued additional warrants for the purchase of 9,712 shares of Series 7 redeemable convertible preferred stock at an exercise price of $10.03 per share in December 2016.

The fair value of warrants to purchase preferred stock were recorded at the date of issuance as a discount to debt and amortized to interest expense over the term of the note. The changes in the fair value of the redeemable convertible preferred stock warrants are recorded in other income and expense.

In March 2017, the Company issued a warrant to purchase 1,388 shares of common stock at an exercise price of $5.94 to a consultant. The Company determined that such warrant meets the requirements for equity classification.

In October 2017, the Company extinguished its debt with SVB and Oxford. All related debt discounts were written off upon repayment of the loan.

Weighted-average assumptions used in computation of the fair value of the redeemable convertible preferred stock warrants are summarized in the table below:



	September 30,		December 31,
	2018		2017

Remaining contractual term (in years)	4.7		5.3
Expected volatility	52.66	%	59.06	%
Risk-free interest rate	2.67	%	2.16	%
Dividend yield	—	%	—	%