10.

Preferred Stock Warrants

The Company classified its preferred stock warrants as liabilities on the accompanying consolidated balance sheets. During the year ended December 31, 2015, $19.3 million of the fair value of the warrant liability was reclassified to redeemable convertible preferred stock and then into additional paid-in capital in stockholders’ equity (deficit) on conversion of redeemable convertible preferred stock into common stock on the closing of the IPO. The warrants were no longer outstanding at December 31, 2015. The fair value of the warrants was estimated to be $1.8 million as of December 31, 2014. Refer to Note 4 for the valuation technique and assumptions used in estimating the fair value of the warrants.

The key terms of the convertible preferred stock are summarized in the following table:


			Warrants Outstanding
	Warrants Outstanding December 31, 2014		Warrants Outstanding December 31, 2013		Exercise Price		Expiration
Series A preferred stock warrants		—		22,914	$	11.324	Various dates in 2014
Series B preferred stock warrants		10,414		10,414		7.45	July 31, 2018
Series B-1 preferred stock warrants		47,060		47,060		7.45	June 30, 2018
Series B-1 preferred stock warrants		746,295		746,295		2.6075	Various dates in 2016 – 2021
Series C preferred stock warrants		171,566		171,566		5.125	Various dates in 2022 – 2023

Total preferred stock warrants		975,335		998,249

The warrants were immediately exercisable in whole or in part over the term of the warrants. During the year ended December 31, 2015, 31,778 of the Series B-1 warrants were cash exercised at an exercise price of $7.45 per share, 412,508 of the Series B-1 warrants were cash exercised at an exercise price of $2.6075 per share and 37,385 of the Series C warrants were cash exercised at an exercise price of $5.215 per share, resulting in total aggregate cash proceeds to the Company of $1.5 million.

On the closing of the Company’s IPO, all of the remaining outstanding preferred stock warrants were net exercised at the IPO price of $17.00 per share, which resulted in 6,499 shares of common stock being issued upon the net exercise of outstanding warrants to purchase 10,414 shares of Series B preferred stock, 291,164 shares of common stock being issued upon the net exercise of outstanding warrants to purchase 349,054 shares of Series B-1 preferred stock and 93,017 shares of common stock being issued upon the net exercise of outstanding warrants to purchase 134,180 shares of Series C preferred stock.

During the years ended December 31, 2014 and 2013, no warrants were exercised.