The Company grants options, RSUs, and performance shares under the 2016 Incentive Plan (the “2016 Plan”), under which awards may be granted to all employees. Vesting periods under this plan are generally four years for options and RSUs and three years for performance shares. As of March 31, 2024, approximately 2.8 million shares were reserved for future grants under the 2016 Plan.

In February 2024, the Company’s Board of Directors approved 2024 Inducement Equity Incentive Plan (the “2024 Inducement Plan”), under which Stock Options, Restricted Stock, Restricted Stock Units, Stock Appreciation Rights, Performance Units, Performance Shares, and other stock or cash awards can be granted to personnel for positions of substantial responsibility. As of March 31, 2024, approximately 0.9 million shares were reserved for future grants under the 2024 Inducement Plan.

Additionally, the Company sponsors an Employee Stock Purchase Plan (the “ESPP”). The terms of the plan include a look-back feature that enables employees to purchase stock semi-annually at a price equal to 85% of the lesser of the fair market value at the beginning of the offering period or the purchase date. The duration of each offering period is generally six months. As of March 31, 2024, approximately 0.6 million shares were available for issuance under the ESPP.

Stock option activity was as follows:


(In thousands, except per share amounts)	Number of Shares		Weighted Average Exercise Price Per Share
Outstanding as of December 31, 2023		866	$	30.70
Granted		—	$	—
Exercised		—	$	—
Cancelled		—	$	—
Expired		—	$	—
Outstanding as of March 31, 2024		866	$	30.70

Time-based RSU activity was as follows:


(In thousands, except per share amounts)	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Outstanding as of December 31, 2023		1,567		$	22.83
Granted		459		$	14.90
Vested		(85	)	$	19.93
Cancelled		(41	)	$	22.15
Outstanding as of March 31, 2024		1,900		$	20.87

Since 2020, the Company’s executive officers were granted performance-based restricted stock units (“PSUs”) under the 2016 Plan with vesting occurring at the end of a three-year period if performance conditions are met. The number of PSUs earned and eligible to vest are determined based on achievement of the pre-determined performance conditions and the recipients’ continued service with the Company. The number of stock units to vest could range from 0% to 150% of the target shares granted. At the end of each reporting period, the Company evaluates the probability of achieving the performance conditions and records the related stock-based compensation expense based on performance to date over the service period.

In February 2024, the Company granted PSUs under the 2024 Inducement Plan to its newly-hired Chief Executive Officer with 1/3 of the target PSUs being allocated to each tranche and vesting occurring at the end of each anniversary of the vesting commencement date over a three-year period. The number of PSUs to vest could range from 0% to 150% of the target shares granted and are determined based on achievement of the pre-determined market condition and the recipients’ continued service with the Company. The grant date fair value was determined using the Monte Carlo valuation method. The stock-based compensation expense relating to PSUs with a market condition is recognized ratably from the service inception date to the vesting date for each tranche.

PSU activity was as follows:


(In thousands, except per share amounts)	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Outstanding as of December 31, 2023		417		$	24.76
Granted		456		$	20.71
Vested		—		$	—
Cancelled		(296	)	$	27.36
Outstanding as of March 31, 2024		577		$	20.23

Valuation and Expense Information

The following table sets forth the stock-based compensation expense resulting from stock options, RSUs (time-based and performance-based) and the ESPP included in the Company’s unaudited condensed consolidated statements of operations:


	Three Months Ended
(In thousands)	March 31, 2024		April 2, 2023
Cost of revenue	$	365	$	351
Research and development		698		1,065
Sales and marketing		1,237		1,431
General and administrative		2,244		1,818
Total	$	4,544	$	4,665

As of March 31, 2024, $36.8 million of unrecognized compensation cost related to unvested RSUs (time-based and performance-based) expected to be recognized over a weighted-average period of 2.4 years.