| Three Months Ended April 30, | ||||||
| 2024 | 2023 | |||||
| (unaudited, in thousands) | ||||||
| Stock-based compensation: | ||||||
| Cost of revenue | $ | 607 | $ | 941 | ||
| Research and development | 17,621 | 18,361 | ||||
| Selling, general and administrative | 7,808 | 7,963 | ||||
| Total stock-based compensation | $ | 26,036 | $ | 27,265 | ||
| Three Months Ended April 30, | ||||||
| 2024 | 2023 | |||||
| (unaudited, in thousands) | ||||||
| Acquisition-related costs: | ||||||
| Cost of revenue | $ | 757 | $ | 757 | ||
| Research and development | — | — | ||||
| Selling, general and administrative | 520 | 520 | ||||
| Total acquisition-related costs | $ | 1,277 | $ | 1,277 | ||
The difference between GAAP and non-GAAP gross margin was 2.5% and 2.7%, or $1.4 million and $1.7 million, for the three months ended April 30, 2024 and April 30, 2023, respectively. The differences were due to the effect of stock-based compensation and the amortization of acquisition-related costs.
