Table of Contents ENPHASE ENERGY, INC. NOTES TO CONSOLIDATED FINANCIAL STATEMENTS In the years ended December 31, 2023, 2022 and 2021, one customer accounted for approximately 40%, 37% and 34%, respectively, of total net revenues. 19. NET INCOME PER SHARE Basic net income per share is computed by dividing net income by the weighted average number of shares of common stock outstanding during the period. Diluted net income per share is computed in a similar manner, but it also includes the effect of potential common shares outstanding during the period, when dilutive. Potential common shares include stock options, RSUs, PSUs, shares to be purchased under the Company’s ESPP, the Notes due 2023, Notes due 2025, Notes due 2026, Notes due 2028 and the 2025 Warrants. The following table presents the computation of basic and diluted net income per share for the periods presented: Years Ended December 31, 2023 2022 2021 (In thousands, except per share data) Numerator: Net income $ 438,936 $ 397,362 $ 145,449 Convertible senior notes interest and financing costs, net of tax 2,573 2,629 177 Adjusted net income $ 441,509 $ 399,991 $ 145,626 Denominator: Shares used in basic per share amounts: Weighted average common shares outstanding 136,376 135,349 134,025 Shares used in diluted per share amounts: 136,376 135,349 Weighted average common shares outstanding used for basic calculation 134,025 Effect of dilutive securities: Employee stock-based awards 1,782 3,407 4,918 Notes due 2023 638 900 900 Notes due 2024 — — 768 2024 Warrants — — 647 Notes due 2025 — — 929 2025 Warrants 419 659 691 Notes due 2026 2,057 2,057 — Notes due 2028 2,018 2,018 — Weighted average common shares outstanding for diluted calculation 143,290 144,390 142,878 Basic and diluted net income per share Net income per share, basic $ 3.22 $ 2.94 $ 1.09 Net income per share, diluted $ 3.08 $ 2.77 $ 1.02 Diluted earnings per share for the year ended December 31, 2023 and 2022 includes the dilutive effect of potentially dilutive common shares by application of the treasury stock method for stock options, RSUs, PSUs, ESPP, the 2025 Warrants, and includes potentially dilutive common shares by application of the if-converted method for the Notes due 2023, Notes due 2025, Notes due 2026 and Notes due 2028. To the extent these potential common shares are antidilutive, they are excluded from the calculation of diluted net income per share. Enphase Energy, Inc. | 2023 Form 10-K | 120