Stockholders' Equity (Tables)

9 Months Ended

Oct. 02, 2020

Stockholders Equity Note [Abstract]

Schedule of Compensation Cost

The cost that has been charged against income for stock-based compensation is set forth below (in thousands):

	Three Months Ended				Nine Months Ended
	October 2, 2020		September 27, 2019		October 2, 2020		September 27, 2019
Employee stock options	$	2,469	$	2,178	$	7,206	$	5,770
Restricted stock		119		77		273		236
Restricted stock units		415		246		1,238		1,661
Performance stock units		54		—		54		—
Nonemployee stock options		69		57		194		111
Total stock-based compensation expense	$	3,126	$	2,558	$	8,965	$	7,778

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

The Company recorded stock-based compensation costs in the following categories (in thousands):

	Three Months Ended				Nine Months Ended
	October 2, 2020		September 27, 2019		October 2, 2020		September 27, 2019
Cost of sales	$	30	$	7	$	82	$	43
General and administrative		1,307		1,082		3,601		2,878
Marketing and selling		807		692		2,674		2,553
Research and development		982		777		2,608		2,304
Total stock-based compensation expense, net		3,126		2,558		8,965		7,778
Amounts capitalized as part of inventory		287		258		847		723
Total stock-based compensation expense, gross	$	3,413	$	2,816	$	9,812	$	8,501

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The risk-free rate is based on the U.S. Treasury yield curve corresponding to the expected term at the time of the grant.

	Three Months Ended						Nine Months Ended
	October 2, 2020			September 27, 2019			October 2, 2020			September 27, 2019
Expected dividend yield		0	%		0	%		0	%		0	%
Expected volatility		53	%		53	%		53	%		53	%
Risk-free interest rate		0.31	%		1.55	%		0.53	%		2.40	%
Expected term (in years)		5.72			5.67			5.72			5.67

Schedule of Share-based Compensation, Stock Options, Activity

A summary of stock option activity under the Plan for the nine months ended October 2, 2020 is presented below:

	Stock Options (in 000’s)			Minimum Exercise Price		Maximum Exercise Price
Outstanding at January 3, 2020		4,326
Granted		616
Exercised		(1,146	)
Forfeited or expired		(14	)
Outstanding at October 2, 2020		3,782		$	5.05	$	51.42
Exercisable at October 2, 2020		2,594

Schedule of Share-based Compensation, Restricted Stock, Restricted Stock Units and Performance Stock Units Activity

A summary of restricted stock, RSUs and PSUs activity under the Plan for the nine months ended October 2, 2020 is presented below:

	Restricted Stock (in 000’s)			Restricted Stock Units (in 000’s)			Performance Stock Units (in 000’s)
Unvested at January 3, 2020		11			104			—
Granted		11			127			15
Vested		(11	)		(93	)		—
Forfeited or expired		—			(1	)		—
Unvested at October 2, 2020		11			137			15