Stockholders’ Equity


(a)	Convertible Preferred Stock

The authorized, issued, and outstanding shares of convertible preferred stock as of March 31, 2018 and December 31, 2017 are as follows:



(in thousands)	Shares Authorized	Shares Issued and Outstanding	Aggregate Liquidation Preference
Series C	22,862	4,572	$	38,820
Series D	28,301	5,660	25,980
Series E	11,839	2,348	17,537
Series F	37,253	7,256	37,334
Series G	29,223	4,805	28,783
	129,478	24,641	$	148,454

Immediately prior to the closing of the IPO on April 30, 2018 all shares of the outstanding convertible preferred stock automatically converted into an aggregate of 24.6 million shares of common stock.


(b)	Common Stock

At March 31, 2018 and December 31, 2017 the Company was authorized to issue 190.0 million shares of common stock with 3.1 million and 3.0 million shares of common stock issued and outstanding.


(c)	2000 and 2001 Stock Plans

On August 29, 2000, the Board of Directors adopted the 2000 Stock Plan (the "2000 Plan"). As of December 31, 2000, the Company had reserved 17.2 million shares of common stock for issuance under the 2000 Plan to employees, directors, and consultants of the Company. The Company is no longer issuing options under the 2000 Plan.

On April 24, 2001, the Board of Directors adopted the 2001 Stock Plan (the "2001 Plan"). Under the 2001 Plan, either incentive or nonqualified options to purchase the Company’s common stock were granted at prices determined by the Board of Directors. Options granted under the 2001 Plan typically vest over 4 ‑ 5 years and have terms of up to 10 years from the date of grant. All vested options must be exercised within three months of termination of employment.

As of March 31, 2018 and December 31, 2017 the Company had reserved 9.0 million shares of common stock for issuance under the 2001 Plan to employees, directors, and consultants of the Company. Of these shares, a total of 1.3 million and 1.7 million shares, respectively were available for issuance as of March 31, 2018 and December 31, 2017.

The following table summarizes the Company’s stock option activity during the three months ended March 31, 2018:



(in thousands)	Number of shares		Weighted average exercise price	Weighted average remaining contractual term (years)	Aggregate intrinsic value
Outstanding, December 31, 2017	5,369		$1.09	7.4	$29,863
Options granted	347		$9.70
Options exercised	(76	)	$0.81
Options canceled	(10	)	$1.66
Outstanding, March 31, 2018	5,630		$1.62	7.4	$47,168
Options exercisable at March 31, 2018	2,439		$0.85	6.8	$22,469
Options vested as of March 31, 2018 and expected to vest after March 31, 2018	4,518		$1.63	8.0	$43,536

The aggregate intrinsic value in the table above represents the total pretax value, based on the Company’s common stock valuation of $10.00 at March 31, 2018 that would have been received by the option holders had all option holders exercised their in‑the‑money options on March 31, 2018.

Total intrinsic value of options exercised for the three months ended March 31, 2018 and 2017 was $678 thousand and $34 thousand, respectively. The Company received proceeds of $61 thousand from the exercise of options for both the three months ended March 31, 2018 and 2017, respectively.

Total compensation cost related to nonvested awards not yet recognized is $2.8 million, which will be recognized during the remainder of 2018 and subsequent years as follows:



(in thousands)
2018	$	581
2019	707
2020	614
2021	551
2022	370
2023	6
	$	2,829