Personalis Inc

Note 5. Fair Value Measurements

The following tables show the Company’s financial assets measured at fair value on a recurring basis and the level of inputs used in such measurements as of March 31, 2024 and December 31, 2023 (in thousands):

Marketable debt securities at March 31, 2024 have maturities due in less than 12 months. No security has been in a continuous unrealized loss position for more than 12 months and the Company does not consider any of its marketable debt securities to be impaired.

Tempus Warrants

The Black-Scholes option-pricing model was used to estimate fair value of the warrants issued to Tempus AI, Inc. (formerly known as Tempus Labs, Inc., and referred to herein as "Tempus") at the date of issuance, November 28, 2023, and at each subsequent balance sheet date. Assumptions used are listed below, which are Level 3 fair value inputs. Expected term is equal to the remaining contractual periods of each of the two warrants. Expected volatility was based on the Company's actual historical volatility over the expected terms of the warrants. The risk-free interest rate was based on the U.S. Treasury yield curve over the expected term of the warrants. Refer to Note 8 for further information about the warrants issued to Tempus.

The following table sets forth a summary of the changes in fair value of the Tempus Warrants, which are classified as Level 3 financial instruments (in thousands):

Note 6.