10. Net Loss per Share Attributable to Portola Common Stockholders

Basic net loss per share attributable to Portola Common Stockholders has been computed by dividing the net loss attributable to Portola Common Stockholders by the weighted-average number of shares of Common Stock outstanding during the period. Diluted net loss per share attributable to Portola Common Stockholders is calculated by dividing net loss attributable to Portola Common Stockholders by the weighted average number of shares of Common Stock and potential dilutive securities outstanding during the period.

The following common stock equivalent shares were excluded from the computation of diluted net loss per share attributable to Portola Common Stockholders for the three and nine months ended September 30, 2017 and 2016 because including them would have been anti-dilutive:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Stock options to purchase common stock		6,421,103		5,888,149		6,421,103		5,888,149
Performance stock options		176,117		271,122		176,117		271,122
Common stock warrants		1,500		1,500		1,500		1,500
Restricted stock units		637,772		559,077		637,772		559,077
Performance stock units		316,961		286,052		316,961		286,052
Employee stock purchase plan		7,759		10,019		7,759		10,019

Up to 1 million shares may be contingently issued, if certain performance conditions are met under an agreement with one of our contract manufacturers.