During December 2020, the Company completed a public offering in which the Company issued and sold 6,571,428 shares of common stock at a public offering price of $70.00 per share, which resulted in aggregate net proceeds of $431.9 million, net of underwriter discounts, commissions and offering costs of $28.1 million.

In October 2019, the Company entered into an Equity Distribution Agreement (Distribution Agreement) with Piper Sandler Companies, formerly Piper Jaffray & Co. (Piper Sandler), pursuant to which the Company may offer and sell from time-to-time in an “at-the-market offering,” at its option, up to an aggregate of $100.0 million of shares of the Company’s common stock through Piper Sandler, as sales agent. During year ended December 31, 2020, the Company sold 2,593,637 shares of its common stock resulting in proceeds to the Company of $64.1 million, net of offering costs of $1.6 million.

In September 2018, the Company adopted the 2018 Employee Stock Purchase Plan (the 2018 ESPP) initially providing participating employees with the opportunity to purchase an aggregate of 311,850 shares of the Company’s common stock. The number of shares of the Company’s common stock reserved for issuance under the 2018 ESPP increased, pursuant to the terms of the 2018 ESPP, by additional shares equal to 1% of the Company’s then-outstanding common stock, effective as of January 1 of each year. The number of shares of the Company’s common stock reserved for issuance under the 2018 ESPP increased by 486,657 and 390,371 shares in 2021 and 2020, respectively. The first offering period under the 2018 ESPP commenced on January 1, 2020. During the six months ended June 30, 2021, the Company issued 12,050 shares of common stock under the 2018 ESPP. As of June 30, 2021, 1,489,159 shares remained available for purchase.

All of the Company’s employees are eligible to participate in the 2018 ESPP, provided they meet certain employment requirements. On each offering commencement date, each participant will be granted the right to purchase, on the last business day of the offering period, a number of shares of the Company’s common stock determined by multiplying $2,083 by the number of full months in the offering period and dividing that product by the closing price of the Company’s common stock on the first day of the offering period. On the commencement date of each offering period, each eligible employee may authorize up to a maximum of 15% of the compensation he or she receives during the offering period to be deducted by the Company during the offering period. Under the terms of the 2018 ESPP, the purchase price shall be determined by the Company’s board of directors for each offering period and will be at least 85% of the applicable closing price of the Company’s common stock. If the Company’s board of directors does not make a determination of the purchase price, the purchase price will be 85% of the lesser of the closing price of the Company’s common stock on the first business day of the offering period or the last business day of the offering period.

In the Fourth Amendment to the Company’s Incentive Share Plan (the Incentive Plan) adopted in March 2018, the Company was authorized to issue up to an aggregate of 6,199,477 incentive units pursuant to the Incentive Plan. Generally, incentive units were granted at no less than fair value as determined by the board of managers and had vesting periods ranging from one to four years. The Incentive Plan was terminated in September 2018. In September 2018, the Company’s board of directors adopted and the Company’s stockholders approved the 2018 Stock Incentive Plan (the 2018 Plan), which became effective upon the effectiveness of the registration statement on Form S-1 for the Company’s initial public offering. The number of common shares initially available for issuance under the 2018 Plan equaled the sum of (1) 4,067,007 shares of common stock; plus (2) the number of shares of common stock (up to 1,277,181) issued in respect of incentive units granted under the Incentive Plan that are subject to vesting immediately prior to the effectiveness of the registration statement that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right; plus (3) an annual increase on the first day of each fiscal year beginning with the fiscal year ended December 31, 2019 and continuing to, and including, the fiscal year ending December 31, 2028, equal to the lowest of 4,989,593 shares of the Company’s common stock, 4% of the number of shares of the Company’s common stock outstanding on the first day of the fiscal year and an amount determined by the Company’s board of directors. The increase in the number of authorized shares for fiscal years December 31, 2021 and 2020 was 1,946,628 and 1,561,485, respectively. Common shares subject to outstanding equity awards that expire or are terminated, surrendered, or canceled without having been fully exercised or are forfeited in whole or in part shall be available for future grants of awards.

During the six months ended June 30, 2021, the Company recognized compensation expense of $24,895,874 relating to the issuance of incentive awards, and at June 30, 2021, there was $67,855,903 of compensation expense that is expected to be amortized over a weighted average period of approximately two years.

The fair value of the stock options granted during the six months ended June 30, 2021 and 2020 was determined using the Black-Scholes option pricing model with the following assumptions:

	June 30, 2021			June 30, 2020
Expected volatility	75.9-78.0%			70.3-74.7%
Expected term (years)	5.5-7.0			5.5-7.0
Risk free interest rate	0.5%-1.2%			0.3%-1.6%
Expected dividend yield		0	%	0%
Exercise price	$66.82-$82.21			$31.95-$50.00

Given the Company’s common stock has not been trading for a sufficient period of time, the Company utilizes a collection of volatilities of peer companies to estimate the expected volatility of its common stock. The expected term is calculated utilizing the simplified method.

The following table provides a summary of the stock option activity under the 2018 Plan during the six months ended June 30, 2021. These amounts include stock options granted to employees, directors and consultants.

Stock options	Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2020		4,321,882		$	26.35
Granted		1,491,974		$	77.53
Exercised		(361,706	)	$	21.41
Forfeited		(19,225	)	$	50.50
Outstanding at June 30, 2021		5,432,925		$	40.65		8.40	$	199,393,804
Exercisable at June 30, 2021		2,172,181		$	22.78		7.69	$	117,772,016

The following table provides a summary of the restricted stock grant activity under the Incentive Plan during the six months ended June 30, 2021. These amounts include restricted stock granted to employees, directors and consultants.

Restricted shares	Shares			Weighted Average Grant Date Fair Value Per Share
Unvested restricted stock at December 31, 2020		238,712		$	16.00
Vested		(125,028	)	$	16.00
Unvested restricted stock at June 30, 2021		113,684		$	16.00

The following table provides a summary of the restricted stock unit activity under the 2018 Plan during the six months ended June 30, 2021. These amounts include restricted stock units granted to employees.

Restricted stock units	Shares			Weighted Average Grant Date Fair Value Per Share
Unvested restricted stock units at December 31, 2020		133,049		$	20.01
Vested		(40,344	)	$	19.36
Cancelled		(387	)	$	19.36
Unvested restricted stock units at June 30, 2021		92,318		$	20.30

At June 30, 2021, there were 5,095,090 stock options under the 2018 Plan, 106,790 restricted shares under the Incentive Plan, and 79,474 restricted stock units under the 2018 Plan that vested and are expected to vest.