Note 4—Net Income Per Share
Basic net income per share attributable to common stockholders is computed by dividing the net income by the weighted-average number of shares of common stock outstanding for the period. Diluted net income per share is computed by dividing net income, adjusted on an if-converted basis for the period, by the weighted-average number of shares of common stock and potentially dilutive common stock outstanding during the period. The dilutive effect of outstanding stock-based compensation awards and convertible senior notes are computed using the treasury stock method and the if-converted method, respectively.
The following table presents the calculation of basic and diluted net income per share for periods presented (in thousands, except per share amounts):
 Year Ended  
December 31,
 202520242023
Numerator:
Net income$162,982 $303,281 $307,568 
Add back interest expense, net of tax attributable to assumed conversion of convertible senior notes10,125 6,325 6,336 
Net income attributable to common stockholders—diluted$173,107 $309,606 $313,904 
Denominator:
Weighted average common shares outstanding—basic102,356 114,944 122,503 
Dilutive effect of outstanding stock-based compensation awards2,596 2,063 2,928 
Dilutive effect of assumed conversion of convertible senior notes19,162 14,714 14,714 
Weighted average common shares outstanding—diluted124,114 131,721 140,145 
Net income per share attributable to common stockholders—basic$1.59 $2.64 $2.51 
Net income per share attributable to common stockholders—diluted$1.39 $2.35 $2.24 
Outstanding stock-based compensation awards excluded from net income per diluted share because their effect would have been anti-dilutive
3,497 6,296 4,894 

About Earnings Per Share Disclosures

The earnings per share disclosure breaks down the calculation from net income to both basic and diluted EPS, revealing the full impact of a company's capital structure on per-share economics. The reconciliation between basic and diluted share counts exposes how many stock options, RSUs, convertible securities, and warrants are potentially dilutive to existing shareholders.

Key signals: a widening gap between basic and diluted shares indicates growing dilution from equity compensation or convertible instruments. Anti-dilutive securities excluded from the diluted calculation deserve attention — they represent latent dilution that will materialize if the stock price rises. Watch for the effect of share buybacks on per-share metrics: EPS growth driven primarily by repurchases rather than income growth signals weakening fundamentals. Compare year-over-year changes in the diluted share count against equity compensation expense to assess whether management is effectively managing dilution.