Basic and diluted net income (loss) per share is presented in conformity with the two-class method required for participating securities. The Company’s redeemable convertible preferred stock were participating securities as the holders of the redeemable convertible preferred stock were entitled to participate in dividends with common stock. In periods of net income, net income is attributed to common stockholders and participating securities based on their participation rights, and basic net income per share is calculated by dividing the net income attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period.

Net losses were not allocated to the redeemable convertible preferred stock as the holders of the redeemable convertible preferred stock did not have a contractual obligation to share in any losses. Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. The Company’s common stock which was converted from redeemable convertible preferred stock upon the closing of the IPO is weighted based on the period of time it was outstanding after conversion.

Diluted net income per share attributable to common stockholders adjusts basic net income per share for the potentially dilutive impact of stock options, stock awards, and redeemable convertible preferred stock. As the Company has reported net losses attributable to common stockholders for all periods presented, all potentially dilutive securities are antidilutive and accordingly, basic net loss per share attributable to common stockholders equals diluted net loss per share attributable to common stockholders.

The following weighted-average potentially dilutive shares are excluded from the calculation of diluted earnings per share as they are anti-dilutive:

	Year Ended December 31,
	2021		2020		2019
Shares of common stock issuable upon conversion of redeemable convertible preferred stock		33,431,158		82,428,289		74,925,035
Shares of common stock issuable upon conversion of Series I warrant		-		1,059,620		-
Restricted stock units and restricted stock awards subject to future vesting		6,155,387		3,826,250		878,693
Shares issuable pursuant to the ESPP		326,819		-		-
Shares of common stock issuable from stock options		9,618,882		15,749,829		17,883,037
Unvested early exercised common stock		-		-		12,254
Total		49,532,246		103,063,988		93,699,019