NET INCOME PER SHARE
Potential common shares are excluded from the diluted net income per share computation to the extent that they would be antidilutive. If the Company reported a net loss for the year, no potentially dilutive securities would be included in the computation of diluted net loss per share. As discussed in Note 11, Debt, the Company has the option to pay cash for the aggregate principal amount due upon the conversion of its 2025 Notes.
For additional information on the Company’s computation, see Note 2, Summary of Significant Accounting Policies. Prior to the Company’s adoption of ASU 2020-06, for the year ended December 31, 2021, the Company used the treasury stock method to calculate dilutive shares on its convertible debt.
The following table sets forth the computation of basic and diluted net income per common share for the years ended December 31, 2023, 2022 and 2021 (in thousands, except per share amounts):
 Year Ended December 31,
 202320222021
Numerator:   
Net income—basic$41,955 $15,909 $41,980 
ASU 2020-06 convertible notes if-converted method adjustment4,114 — — 
Adjusted net income—diluted$46,069 $15,909 $41,980 
Denominator:
Weighted average common shares outstanding—basic46,222 45,521 44,262 
Computation of diluted securities:
ASU 2020-06 convertible notes if-converted method adjustment5,608 — — 
Dilutive effect of stock options51 787 1,030 
Dilutive effect of RSUs96 226 298 
Dilutive effect of conversion premium on the 2022 Notes— — 38 
Dilutive effect of ESPP purchase options
Weighted average common shares outstanding—diluted51,979 46,538 45,630 
Net income per share:
Basic net income per common share$0.91 $0.35 $0.95 
Diluted net income per common share$0.89 $0.34 $0.92 
The following table summarizes the outstanding stock options, RSUs, ESPP purchase options and convertible senior notes that were excluded from the diluted net income per common share calculation because the effects of including these potential shares were antidilutive in the periods presented (in thousands):
 Year Ended December 31,
 202320222021
Weighted average number of stock options6,251 2,821 2,141 
Convertible senior notes (1)
— 6,206 — 
Weighted average number of RSUs1,033 417 116 
Weighted average ESPP purchase options20 13 
     Total7,304 9,451 2,270 
(1) The convertible senior notes were antidilutive for the year ended December 31, 2022, in conjunction with a $5.1 million if-converted method adjustment to the numerator that adds back the interest expense associated with the convertible debt on a post-tax basis under ASU 2020-06.

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.