Stock-based Compensation and Stockholders' Equity

Stock-Based Compensation Activity

The estimated fair value for stock options, which determines the Company’s calculation of stock-based compensation expense, is based on the Black-Scholes option pricing model. Restricted stock units ("RSUs") are valued at the closing market price of the Company’s common stock on the grant date. The Company uses the straight-line method to recognize the fair value of stock-based compensation arrangements.

During the three months ended August 25, 2019, the Company did not grant any options to purchase shares of common stock and awarded 87,000 RSUs.

As of August 25, 2019, the Company has reserved 2.5 million shares of Common Stock for future issuance under its current and former equity plans.

Stock-Based Compensation Expense

The Company’s stock-based awards include stock option grants and RSUs. The Company records compensation expense for stock-based awards issued to employees and directors in exchange for services provided based on the estimated fair value of the awards on their grant dates and is recognized over the required service periods, generally the vesting period.

The following table summarizes stock-based compensation by income statement line item:



	Three Months Ended
(In thousands)	August 25, 2019			August 26, 2018
Cost of sales	$	(26	)	$	101
Research and development	30			25
Selling, general and administrative	524			602
Total stock-based compensation	$	528		$	728

As of August 25, 2019, there was $4.3 million of total unrecognized compensation expense related to unvested equity compensation awards granted under the Landec incentive stock plans. Total expense is expected to be recognized over the weighted-average period of 1.85 years for stock options and 1.91 years for RSUs.

Stock Repurchase Plan

On July 14, 2010, the Company announced that the Board of Directors of the Company had approved the establishment of a stock repurchase plan authorizing the repurchase of up to $10 million of the Company’s common stock. The Company may repurchase its common stock from time to time in open market purchases or in privately negotiated transactions. The timing and actual number of shares repurchased is at the discretion of management of the Company and will depend on a variety of factors, including stock price, corporate and regulatory requirements, market conditions, the relative attractiveness of other capital deployment opportunities and other corporate priorities. The stock repurchase program does not obligate Landec to acquire any amount of its common stock and the program may be modified, suspended or terminated at any time at the Company's discretion without prior notice. During the three months ended August 25, 2019, the Company did not repurchase any of its outstanding common stock.