Stockholders' Equity (Tables)

3 Months Ended

Mar. 29, 2019

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
	March 29, 2019		March 30, 2018
Employee stock option	$	1,430	$	619
Restricted stock		82		51
Restricted stock units		1,104		598
Nonemployee stock options		25		33
Total stock-based compensation expense	$	2,641	$	1,301

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
	March 29, 2019		March 30, 2018
Cost of sales	$	14	$	3
General and administrative		778		519
Marketing and selling		1,171		460
Research and development		678		319
Total stock-based compensation expense, net		2,641		1,301
Amounts capitalized as part of inventory		189		122
Total stock-based compensation expense, gross	$	2,830	$	1,423

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
	March 29, 2019			March 30, 2018
Expected dividend yield		0	%		0	%
Expected volatility		53	%		53	%
Risk-free interest rate		2.43	%		2.61	%
Expected term (in years)		5.67			5.72

Schedule of Share-based Compensation, Stock Options, Activity

A summary of stock option activity under the Plan for the three months ended March 29, 2019 is presented below:

	Stock Options (in 000’s)			Minimum Exercise Price		Maximum Exercise Price
Outstanding at December 28, 2018		3,920
Granted		749
Exercised		(74	)
Forfeited or expired		(1	)
Outstanding at March 29, 2019		4,594		$	1.92	$	43.84
Exercisable at March 29, 2019		2,839

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

A summary of restricted stock and RSU activity under the Plan for the three months ended March 29, 2019 is presented below:

	Restricted Stock (in 000’s)		Restricted Stock Units (in 000’s)
Unvested at December 28, 2018		11		322
Granted		—		19
Vested		—		(178	)
Forfeited or expired		—		(1	)
Unvested at March 29, 2019		11		162