Kodiak Sciences Inc. Notes to Consolidated Financial Statements (in thousands, except share and per share data) 97 Note 15. There were no transfer f s of assets or liabi a lities between the fair value measurement levels during the years ended December 31, 2023 and 2022. 6. Marketable Securities Marketable securities are classified as availabl a e-for-sale. The Company obtains fair value measurement data from third party pricing services and understands the valuation methods and data sources to validate this information. The following tabl a e presents the Company's marketable securities by majo a r security type (in thousands): As of December 31, 2022 Amortized Cost Unrealized Gains Unrealized Losses Fair Value U.S. treasury r securities $ 289,807 $ — $ (1,307) $ 288,500 Total $ 289,807 $ — $ (1,307) $ 288,500 As of December 31, 2023, there were no marketable securities. All marketable securities held as of December 31, 2022 had effe f ctive maturities of less than one year. The unrealized losses for marketable securities related to changes in interest rates. There were no reclassifications out of accumulated other comprehensive income (loss), impairment charges or recoveries and no allowance for credit losses recorded during the twelve months ended December 31, 2023 and 2022. 7. Derivatives The Company uses certain derivative instruments, that are not designated as hedges for accounting purpos r es, which include foreign currency forward contracts. As of December 31, 2023 and 2022, the Company did not have any outstanding derivative instruments. 8. Commitments and Contingencies Leases Palo Alto l , Califor f nia Leases In June 2020, the Company entered into lease agreements for two buildings at 1200 and 1250 Page Mill Road in Palo Alto, California, which are now the Company’s U.S. corporate offi f ces. The facilities are approximately 82,662 square feet and 72,812 square feet, respectively and include offi f ce and labor a atory r space. For 1200 Page Mill Road, the monthly rent during the initial 6.5-year term will be approximately $0.6 million, with annual year-over-year increases of 3% plus certain operating expenses and taxes and total rent abatement of approximately $7.2 million. The Company has an option to extend the lease term for a period of 6.5 years. For 1250 Page Mill Road, the monthly rent during the initial 13-year term will be approximately $0.5 million, with annual year-over-year increases of 3% plus certain operating expenses and taxes and total rent abatement of approximately $6.3 million. The Company has two options to extend the lease term for a period of 5 years each. The Company determined that the renewal options were not reasonabl a y certain at lease inception for the two buildings. The Company executed a $10.9 million cash-collateralized letter of credit, which was subs u equently reduced to $6.2 million as a result of meeting certain reduction requirements specifie f d therein in 2020. The cash collateralizing the letter of credit is classified as restricted cash on the Company’s consolidated balance sheet. The Landlord will provide a tenant improvement allowance of approximately $1.2 million for 1200 Page Mill Road and $10.6 million for 1250 Page Mill Road. As of December 31, 2023, the Company utilized $10.6 million of the tenant improvement allowance for 1250 Page Mill Road. Under ASC 842, the Company classified these leases as operating leases and recorded right-of-use assets and lease liabi a lities on the lease commencement date. Switzerland Lease In April 2020, the Company entered into a lease agreement for offi f ce and labor a atory r space at Rottenstrasse 5 in Visp, Switzerland. The space is approximately 1,000 square meters. The initial lease term is 5 years, with automatic renewals every r 5 years for a maximum lease term of 15 years. The monthly rent during the initial 5-year term will be approximately 32.0 thousand Swiss Francs plus certain operating expenses and taxes. Under ASC 842, the Company classified this lease as an operating lease and recorded a right-of-use asset and lease liabi a lity on the lease commencement date.