Table:
|  | 2019 | 2018 | 2017 |
| --- | --- | --- | --- |
| Stock options | 1,687 | 2,806 | 569 |
| RSUs | 2,352 | 2,580 | 83 |
| ESPP common stock equivalents | 74 | 71 | — |
| ID Checker earnout shares | — | — | 24 |
| Total potentially dilutive common shares outstanding | 4,113 | 5,457 | 676 |
Paragraphs:
Net Income (Loss) Per Share
The Company calculates net income (loss) per share in accordance with FASB ASC Topic 260,Earnings per Share. Basic net income (loss) per share is based on the weighted-average number of common shares outstanding during the period. Diluted net income (loss) per share also gives effect to all potentially dilutive securities outstanding during the period, such as restricted stock units (“RSUs”), stock options, and Employee Stock Purchase Plan ("ESPP") shares, if dilutive. In a period with a net loss position, potentially dilutive securities are not included in the computation of diluted net loss because to do so would be antidilutive, and the number of shares used to calculate basic and diluted net loss is the same.
For the fiscal years ended September 30, 2019, 2018 and 2017, the following potentially dilutive common shares were excluded from the net income (loss)
per share calculation, as they would have been antidilutive (amounts in thousands):
Question:
What is basic net income (loss) per share based on?
Answer: the weighted-average number of common shares outstanding during the period