Company: CSTL
Filing Date: 2025-11-03
Form Type: 10-Q
Source: 0001628280-25-048254
Chunk: 21

Company: CASTLE BIOSCIENCES INC
Filing Date: 2025-11-03
Form: 10-Q
Item: Item 1
Chunk 21
---
$169,636 $244 $(14)$169,866 U.S. government securities - HTM(1)— — — — Total debt securities$169,636 $244 $(14)$169,866 (1)We held no debt securities - HTM as of December 31, 2024.Our U.S. government securities includes both AFS and HTM securities. The AFS securities are available to be sold to meet operating needs or otherwise, but are generally held through maturity. We classify all AFS investments as current assets, as these are readily available for use in current operations. We classify our HTM investments as current assets, as we have the positive intent and ability to hold these investments to maturity, and all such maturities are less than one year from the balance sheet date.We evaluated our U.S. government securities under the AFS and HTM impairment model guidance, respectively, and determined our investment portfolio is comprised of low-risk, investment grade securities.As of September 30, 2025, unrealized losses on our AFS and HTM U.S. government securities are not attributed to credit risk. We believe that an allowance for credit losses is unnecessary because the unrealized losses on certain of our marketable investment securities are due to market factors. The allowance for credit losses was zero as of September 30, 2025 and December 31, 2024.There were no realized gains or losses on sales of debt securities for the three and nine months ended September 30, 2025 and 2024. No credit-related or noncredit-related impairment losses were recorded for the three and nine months ended September 30, 2025 and 2024.Accrued interest receivable for our AFS and HTM U.S. government securities is included in prepaid expenses and other current assets in the condensed consolidated balance sheets. As of September 30, 2025 and December 31, 2024, the accrued interest receivable related to AFS securities was $1.2 million and $0.6 million, respectively. The balance related to HTM securities was immaterial as of September 30, 2025, and no amounts were accrued as of December 31, 2024, as no securities were classified as HTM at that time.Additional information relating to the fair value of marketable investment securities can be found in Note 11.

17

Table of ContentsCASTLE BIOSCIENCES, INC.NOTES TO CON