2. Net Loss Per Share

Basic net loss per share attributable to common stockholders is computed by dividing net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period, less the weighted average unvested common stock subject to repurchase or forfeiture. Diluted net loss per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period.

For purposes of the diluted net loss per share calculation, options to purchase common stock, common stock warrants, and redeemable convertible preferred stock are considered to be common stock equivalents. For 2015, we applied the two-class method to calculate our basic and diluted net loss per share of common stock, as our redeemable convertible preferred stock and common stock are participating securities. The two-class method is an earnings allocation formula that treats a participating security as having rights to earnings that otherwise would have been available to common stockholders. However, the two-class method does not impact the net loss per common share attributable to common stockholders as we were in a loss position for all periods in 2015 and the redeemable convertible preferred stockholders do not participate in losses.

A reconciliation of the denominator used in the calculation of basic and diluted loss per share is as follows (in thousands, except per share amounts):

For all periods presented, we incurred net losses and, therefore, the effect of our outstanding stock options, unvested restricted stock, restricted stock units, common stock warrants, common stock subject to repurchase and redeemable convertible preferred stock was not included in the calculation of diluted loss per share as the effect would be anti-dilutive. The following table contains share totals with a potentially dilutive impact (in thousands):