Basic net loss per common share is calculated by dividing net loss by the weighted-average number of common shares outstanding for the period. Diluted net loss per common share is calculated by dividing the diluted net loss by the weighted average number of common shares outstanding, including potential dilutive common shares assuming the dilutive effect of outstanding stock options and unvested restricted stock units. For periods in which we have reported net losses, diluted net loss per common share is the same as basic net loss per common share, since dilutive common shares are not included if their effect is anti-dilutive.

The following potentially dilutive securities were excluded from the calculation of diluted net loss per common share due to their anti-dilutive effect (in thousands):


	As of March 31,
	2024		2023
Outstanding stock options		8,472		11,851
Unvested restricted stock units		12,775		8,085

As discussed further in Note 10, “Long-Term Obligations”, we have the option to settle the conversion obligation for our 3.00% convertible senior notes due 2025 (the “2025 Notes”) in cash, shares or any combination of the two. Based on our net loss position, there was no impact on the calculation of dilutive loss per common share during the three months ended March 31, 2024 and 2023.

As discussed further in Note 9, “Stockholders’ Equity”, warrants to purchase up to 9,787,563 shares of our common stock are outstanding as of March 31, 2024. These warrants were excluded from the calculation of basic and diluted net loss per common share during the three months ended March 31, 2024 and 2023 as the warrant holders do not have an obligation to share in our losses.