On May 28, 2020, the Company adopted the 2020 Incentive Award Plan (“the 2020 Plan”), which authorized the issuance of (i) up to 3,019,108 shares of the Company’s common stock, (ii) up to 4% of an annual increase on the first day of each year beginning on January 1, 2022 and ending on January 1, 2030, and (iii) any shares of the Company’s common stock subject to awards under the 2014 Plan which are forfeited or lapse unexercised and which following the effective date are not issued under the 2014 Plan. Awards may be issued in the form of restricted stock units, restricted stock, stock appreciation rights, and stock options. As of September 30, 2020, there were 3,145,828 shares available for future issuance under the 2020 Plan.

The following table summarizes stock option activity for the nine months ended September 30, 2020:

	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life
Outstanding as of December 31, 2019		6,340,000		$	3.92		8.22
Granted		420,500			10.46
Exercised		(34,374	)		3.90
Forfeited / cancelled		(474,900	)		4.37
Outstanding as of September 30, 2020		6,251,226		$	4.32		7.53
Vested and exercisable as of December 31, 2019		2,684,160		$	3.58		7.41
Vested and exercisable as of September 30, 2020		3,643,514		$	3.72		6.88

The Company recognized $0.6 million and $0.5 million of stock-based compensation expense related to stock options for the three months ended September 30, 2019 and 2020, respectively, and $2.1 million and $1.7 million for the nine months ended September 30, 2019 and 2020, respectively. As of December 31, 2019 and September 30, 2020, the Company had $5.2 million, and $4.1 million, respectively, of unrecognized stock-based compensation expense that is expected to be recognized over a weighted-average period of 2.6 years, and 2.5 years, respectively.

The grant date fair value of stock options granted during the nine months ended September 30, 2020 was estimated at the time of grant using the Black-Scholes option-pricing model and utilized the following weighted average assumptions:

	Nine Months Ended September 30,
Fair value of common stock (per share)	$	10.46
Expected term (in years)	5.9 — 6.3
Risk-free interest rate	1.7%
Expected volatility	36.3% — 36.6%
Dividend yield	—%

The weighted average fair value of stock options granted during the nine months ended September 30, 2020 was estimated to be $3.97 per share. The aggregate intrinsic value of options exercised during the nine months ended September 30, 2020 was $1.5 million, and the aggregate intrinsic value of options outstanding and options exercisable as of September 30, 2020 was $296.7 million and $175.1 million, respectively.

The following table summarizes activity for restricted stock units (“RSUs”) for the nine months ended September 30, 2020:

	Shares			Weighted Average Grant Date Fair Value per Share
Unvested and outstanding as of December 31, 2019		408,000		$	4.01
Granted		2,042,286			11.56
Vested		(237,334	)		3.86
Forfeited / cancelled		(7,000	)		11.57
Unvested and outstanding as of September 30, 2020		2,205,952		$	10.99

The Company recognized $0.0 million and $3.7 million of stock-based compensation expense related to RSUs for the three months ended September 30, 2019 and 2020, respectively, and $0.1 million and $7.0 million for the nine months ended September 30, 2019 and 2020, respectively. As of December 31, 2019 and September 30, 2020, the Company had $1.3 million and $17.9 million, respectively, of unrecognized stock-based compensation expense that is expected to be recognized over a weighted-average period of 2.4 years and 1.8 years, respectively.

As a result of completing its IPO in June 2020, the Company commenced the recognition of compensation expense for 510,278 RSUs that vest upon the occurrence of a liquidity event, which includes an IPO, and continuous service that generally ranges from 12 to 48 months.

In February 2020, the Company granted 367,782 RSUs to its chief executive officer that vest upon the achievement of performance-based conditions, which includes Revenue and EBITDA targets for fiscal year 2022, and the achievement of a liquidity event, which includes a change of control or an IPO. As a result of completing its IPO in June 2020, and the probability of achieving the performance-based conditions, the Company commenced recognition of compensation expense.

Certain of the Company’s RSU grants are subject to acceleration upon a change of control and termination within 12 months, and upon death, disability, retirement and certain “good leaver” circumstances.

During the years ended December 31, 2014 and 2015, the Company granted awards of 4,751,874 shares of restricted common stock (the “RSAs”).

The following table summarizes the activity related to the Company’s RSAs for the nine months ended September 30, 2020:

For the three and nine months ended September 30, 2019, the expense related to the RSAs was immaterial. For the three and nine months ended September 30, 2020, the expense related to the RSAs was $0.0 and $0.2 million, respectively. As of September 30, 2020, there was no remaining unrecognized stock-based compensation expense related to the RSAs.