9.Stock-based compensation

Stock-based compensation expense is measured on the grant date based on the fair value of the award. Stock-based compensation expense is recognized on a straight-line basis over the requisite service period for awards expected to vest. The estimated grant date fair value of stock options was determined using a Black-Scholes valuation model using the following weighted-average assumptions for the periods indicated:

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The expected volatility is based on the historical volatility of the Company’s common stock. The risk-free interest rate is based on the United States Treasury yield curve in effect on the date of grant for the respective expected life of the option. The expected life represents the time the options granted are expected to be outstanding. The expected life of options granted is derived from historical data on Ulta Beauty stock option exercises. Forfeitures of stock options are estimated at the grant date based on historical rates of stock option activity and reduce the stock-based compensation expense recognized. The Company does not currently pay a regular dividend.

The Company granted 42 and 48 stock options during the 39 weeks ended October 28, 2023 and October 29, 2022, respectively. Stock-based compensation expense for stock options was $1,742 and $1,646 for the 13 weeks ended October 28, 2023 and October 29, 2022, respectively. Stock-based compensation expense for stock options was $4,961 and $6,152 for the 39 weeks ended October 28, 2023 and October 29, 2022, respectively. The weighted-average grant date fair value of these stock options was $199.15 and $149.14 for the 39 weeks ended October 28, 2023 and October 29, 2022, respectively. At October 28, 2023, there was approximately $13,028 of unrecognized stock-based compensation expense related to unvested stock options.

There were 48 and 58 restricted stock units issued during the 39 weeks ended October 28, 2023 and October 29, 2022, respectively. Stock-based compensation expense for restricted stock units was $4,959 and $4,544 for the 13 weeks ended October 28, 2023 and October 29, 2022, respectively. Stock-based compensation expense for restricted stock units was $14,252 and $13,983 for the 39 weeks ended October 28, 2023 and October 29, 2022, respectively. At October 28, 2023, there was approximately $32,630 of unrecognized stock-based compensation expense related to restricted stock units.

There were 33 and 37 performance-based restricted stock units issued during the 39 weeks ended October 28, 2023 and October 29, 2022, respectively. Stock-based compensation expense for performance-based restricted stock units was $5,237 and $3,489 for the 13 weeks ended October 28, 2023 and October 29, 2022, respectively. Stock-based compensation expense for performance-based restricted stock units was $14,264 and $12,419 for the 39 weeks ended October 28, 2023 and October 29, 2022, respectively. At October 28, 2023, there was approximately $28,755 of unrecognized stock-based compensation expense related to performance-based restricted stock units.