In July 2018, the Board adopted the 2018 Equity Incentive Plan (the "2018 Plan"). The 2018 Plan became effective in connection with the Company's initial public offering ("IPO"). The number of shares reserved for issuance under the 2018 Plan increases automatically on January 1 of each year beginning in 2019 and continuing through 2028 by a number of shares of common stock equal to the lesser of (x) 5% of the total outstanding shares of the Company’s common stock and common stock equivalents as of the immediately preceding December 31 (rounded to the nearest whole share) and (y) a number of shares determined by the Company's Board.

Pursuant to the 2018 Plan, the Company issued stock options to employees and directors. The option price, number of shares, and grant date are determined at the discretion of the Board. For so long as the option holder performs services for the Company, the options generally vest over 48 months, on a monthly or quarterly basis, with certain options subject to an initial annual cliff vest, and are exercisable for a period not to exceed ten years from the date of grant.

The summary of the Company’s stock option activity is as follows:


	Number of Options			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value
						(In years)		(In thousands)
Outstanding at September 30, 2023		8,549,957		$	13.99		3.6	$	1,689
Exercised		(292,812	)	$	12.09
Forfeited		(25,140	)	$	14.35
Outstanding at December 30, 2023		8,232,005		$	14.06		3.4	$	25,387

As of December 30, 2023 and September 30, 2023, all outstanding stock options have vested and the Company had no unrecognized stock-based compensation expense related to stock options.

Pursuant to the 2018 Plan, the Company issues RSUs to employees and directors. RSUs vest quarterly over the service period, which is generally four years, with certain awards subject to an initial annual cliff vest. The summary of the Company’s RSU activity is as follows:


	Number of Units			Weighted-Average Grant Date Fair Value		Aggregate Intrinsic Value
						(In thousands)
Outstanding at September 30, 2023		7,662,035		$	19.42	$	98,917
Granted		8,535,582		$	11.34
Released		(919,938	)	$	17.30
Forfeited		(376,322	)	$	16.69
Outstanding at December 30, 2023		14,901,357		$	14.99	$	255,409
At December 30, 2023
Units expected to vest		12,332,429		$	15.11	$	211,378

As of December 30, 2023, and September 30, 2023, the Company had $168.2 million and $111.6 million of unrecognized stock-based compensation expense related to RSUs, which are expected to be recognized over weighted-average periods of 2.8 and 2.4 years, respectively.

Pursuant to the 2018 Plan, the Company has issued and may issue certain PSUs that vest on the satisfaction of service and performance conditions. The number of outstanding PSUs is based on the target number of share awards. The number of shares vested at the end of the performance period is based on achievement of performance conditions and may include adjustments to reflect the extent to which the corresponding performance goals have been achieved. The number of shares released during the three months ended December 30, 2023, includes performance achievement adjustments of a net reduction of 25,057 units. The summary of the Company’s PSU activity is as follows:


	Number of Units			Weighted-Average Grant Date Fair Value		Aggregate Intrinsic Value
						(In thousands)
Outstanding at September 30, 2023		265,191		$	21.27	$	3,424
Granted		400,216		$	17.38
Released		(80,827	)	$	23.35
Forfeited		—		$	-
Outstanding at December 30, 2023		584,580		$	18.32	$	10,020

As of December 30, 2023, and September 30, 2023, the Company had $5.4 million and $0.3 million of unrecognized stock-based compensation expense related to PSUs, which are expected to be recognized over weighted-average periods of 2.1 and 1.2 years, respectively.

Total stock-based compensation expense by functional category was as follows:


	Three Months Ended
	December 30, 2023		December 31, 2022
(In thousands)
Cost of revenue	$	654	$	570
Research and development		8,979		9,151
Sales and marketing		3,815		4,113
General and administrative		5,910		6,361
Total stock-based compensation expense	$	19,358	$	20,195