Summary of business and significant accounting policies

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Employee benefit plans

Stock-based compensation. Stock-based awards granted to qualified employees, non-employee directors and consultants are measured at fair value and recognized as an expense. The Company primarily issues restricted stock units and accounts for forfeitures as they occur. For service-based awards, stock-based compensation is recognized on a straight-line basis over the requisite service period. For performance and market-based awards which also require a service period, the Company uses graded vesting over the longer of the derived service period or when the performance or market condition is satisfied.

Cash, Cash Equivalents, and Marketable Securities

Cash equivalents and marketable securities. Cash equivalents consist of investments in money market funds with maturities of three months or less from the date of purchase. Marketable securities consist of U.S. treasury securities, commercial paper, government securities and corporate debt securities, and are classified as available-for-sale securities. The Company views these securities as available to support current operations and has classified all available-for-sale securities as current assets. Available-for-sale securities are carried at fair value with unrealized gains and losses, if any, included in stockholders’ equity. Unrealized gains and losses are charged against other income (expense), net, for declines in fair value below the cost of an individual investment that is deemed to be other than temporary. The Company has not identified any marketable securities as other-than-temporarily impaired for the periods presented. The cost of securities sold is based upon a specific identification method.