The following table sets forth the computation of basic and diluted shares (in thousands):

	Three Months Ended
	March 31, 2020		March 31, 2019
Denominator:
Weighted average common shares outstanding		49,945		48,721
Less: shares of restricted stock subject to repurchase		—		—
Total common shares-basic		49,945		48,721
Effect of dilutive securities:
Options		3		—
Restricted stock awards and units		251		—
Total common shares-diluted		50,199		48,721

Basic net income (loss) per share is computed using the weighted average number of common shares outstanding during the period, excluding any unvested restricted stock awards that are subject to repurchase. Diluted net income (loss) per share is computed using the treasury stock method to calculate the weighted average number of common shares and, if dilutive, potential common shares outstanding during the period. Potential dilutive common shares include unvested restricted stock awards and units and incremental common shares issuable upon the exercise of stock options, less shares from assumed proceeds. The assumed proceeds calculation includes actual proceeds to be received from the employee upon exercise and the average unrecognized stock compensation cost during the period.

For the three months ended March 31, 2020, 2.1 million shares subject to stock options and restricted stock awards and units were excluded from the computation of diluted net income per share as they were anti-dilutive.

For the three months ended March 31, 2019, there was no difference in the weighted average number of common shares used for the calculation of basic and diluted loss per share as the effect of all potentially dilutive shares outstanding was anti-dilutive. A total of 2.1 million shares subject to stock options and restricted stock awards and units were excluded from the computation of diluted net loss per share for the three months ended March 31, 2019, because including them would have been anti-dilutive.