Stockholders' Equity

3 Months Ended

Mar. 31, 2021

Stock Option Plans

We have two stock option plans – the 2004 Equity Incentive Plan (the “2004 Plan”) and the 2012 Incentive Award Plan (the “2012 Plan”). In February 2021, our Board of Directors authorized a 4.7 million increase in the shares available for grant under the 2012 Plan.

During the three months ended March 31, 2021, we issued 1.8 million shares of our common stock upon the exercise of stock options. Certain option holders exercised their options on a “net exercise” basis, pursuant to which they surrendered to us, and we purchased from them at the current market price, enough shares to cover the exercise price and tax withholding requirements arising from the exercise. We purchased 0.8 million shares in connection with such net option exercises, at a total cost of $16.4 million. We recorded these shares as treasury stock on our condensed consolidated balance sheets, at cost.

During the three months ended March 31, 2020, we issued 0.1 million shares of our common stock upon the exercise of stock options.

Stock Repurchase Program

In November 2020, we announced that our Board of Directors approved a program to repurchase up to $200 million of our common stock (the “Stock Repurchase Program”). Unless it is terminated or suspended prior to its expiration, the Stock Repurchase Program will remain in effect until September 30, 2021. The timing and amount of any repurchases pursuant to it will be determined based on market conditions, stock price and other factors. The Stock Repurchase Program does not require us to acquire any specific number of shares and it may be modified, suspended or discontinued at any time without notice. Repurchases pursuant to the Stock Repurchase Program may be made through a variety of methods, including open market purchases, privately negotiated transactions, block trades, accelerated share repurchase transactions or any combination of such methods.

During the three months ended March 31, 2021, we repurchased 1.3 million shares of common stock under the Stock Repurchase Program in open market transactions at an average price of $26.15 per share, for an aggregate purchase price of $33.5 million. As of March 31, 2021, $156.8 million of the current authorization remained available for the repurchase of shares of our common stock.

We recorded repurchased shares as treasury stock on our condensed consolidated balance sheet, at cost. As of March 31, 2021 and 2020, we had 7.9 million and 5.2 million treasury shares outstanding, respectively.

Stock-based compensation

The following table summarizes our stock-based compensation by account:


	Three Months Ended March 31,
	2021		2020

	(in thousands)
Stock-based compensation capitalized in inventory	$	41	$	70
Cost of sales	10		23
Research and development	3,505		2,605
Selling, general and administrative	6,586		5,290
Total stock-based compensation	$	10,142	$	7,988