Personalis, Inc.

Note 5. Fair Value Measurements

The following tables show financial assets and liabilities measured at fair value on a recurring basis and the level of inputs used in such measurements as of December 31, 2025 and 2024 (in thousands):

The amortized costs and fair value of marketable debt securities (excluding cash and money market funds), by contractual maturity, at December 31, 2025 are as follows (in thousands):

Unrealized losses have not been recognized as losses in the consolidated statements of operations as the Company neither intends to sell, nor anticipates that it is more likely than not that the Company will be required to sell the securities before recovery of their amortized cost basis. The declines in fair value are due primarily to changes in market interest rates, rather than credit losses.

Tempus Warrants

The Black-Scholes option-pricing model was used to estimate fair value of the warrants issued to Tempus at the date of issuance, November 28, 2023, and at each subsequent balance sheet date prior to their exercises in full in August 2024. 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, Related Party Transactions, for further information about the warrants issued to Tempus.

The following table sets forth a summary of the changes in fair value of the Company's Level 3 financial instruments (in thousands):