8.    Net Income (Loss) per Share

Basic net income (loss) per share is calculated by dividing net income (loss) by the weighted average shares outstanding during the period, without consideration for common stock equivalents. Diluted net income (loss) per share is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock and if-converted methods. For purposes of the diluted net income (loss) per share calculation, preferred stock, stock options and warrants are considered to be common stock equivalents but have been excluded from the calculation of diluted net income (loss) per share, as their effect would be anti-dilutive for all periods presented, with the exception of the three months ended June 30, 2023.

A reconciliation of basic and diluted net income (loss) per share is as follows (in thousands, except per share data):

As of June 30, 2023 and 2022, and as calculated using the treasury stock method, approximately 41.2 million and 39.6 million of weighted average shares, respectively, were excluded from the calculation of diluted weighted average shares outstanding as their effect was antidilutive.