pre_text: Stock-Based Compensation The Company recognized total stock-based compensation cost related to equity incentive awards as follows (in thousands): A small portion of stock-based compensation cost above is capitalized in accordance with the accounting guidance for internal-use software. The Company uses the straight-line attribution method for recognizing stock-based compensation expense.
table: For the Year Ended December 31,
table: 2019 2018 2017
table: Stock-based compensation cost:
table: Common stock warrants $— $512 $484
table: Stock options 16,489 13,279 11,295
table: Restricted stock units 14,585 90 —
table: Employee stock purchase plan 3,326 2,069 —
table: Total stock-based compensation cost $34,400 $15,950 $11,779
question: Analyse this data from a financial earnings document. What is the change in common stock warrants between 2017 and 2018?