SCHEDULE 13G 0001696926 XXXXXXXX LIVE Class A Common Stock, par value $0.00001 per share 11/07/2025 0002070849 BillionToOne, Inc. 090168105 1035 O'Brien Drive Menlo Park CA 94025 Rule 13d-1(d) NeoTribe Ventures I, L.P. ("NTV I") b DE 2710286.00 0.00 2710286.00 0.00 2710286.00 N 6.6 PN Note to Rows 5 and 7: NeoTribe Partners I, LLC ("NTP I"), the general partner of NTV I, may be deemed to have sole voting and dispositive power over these shares, and Kolluri, the managing member of NTP I, may be deemed to have sole voting and dispositive power over these shares. Note to Row 6: See response to Row 5. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 41,216,110 shares of Class A Common Stock, par value $0.00001 per share ("Common Stock") outstanding as of December 5, 2025, as set forth in the quarterly report on Form 10-Q of BillionToOne, Inc. (the "Issuer") for the quarter ended September 30, 2025, filed with the United States Securities and Exchange Commission (the "Commission") on December 10, 2025 (the "Form 10-Q"). NeoTribe Associates I, L.P. ("NTA I") b DE 109204.00 0.00 109204.00 0.00 109204.00 N 0.3 PN Note to Rows 5 and 7: All shares are held of record by NTV I as nominee for NTA I. NTP I, the general partner of NTA I, may be deemed to have sole voting and dispositive power over these shares, and Kolluri, the managing member of NTP I, may be deemed to have sole voting and dispositive power over these shares. Note to Row 6: See response to Row 5. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 41,216,110 shares of Common Stock outstanding as of December 5, 2025, as set forth in the Form 10-Q. NeoTribe Partners I, LLC ("NTP I") b DE 2819490.00 0.00 2819490.00 0.00 2819490.00 N 6.8 OO Note to Rows 5 and 7: Consists of 2,710,286 shares held of record by NTV I for itself and 109,204 shares held of record by NTV I as nominee for NTA I. NTP I, the general partner of NTV I and NTA I, may be deemed to have sole voting and dispositive power over these shares, and Kolluri, the managing member of NTP I, may be deemed to have sole voting and dispositive power over these shares. Note to Row 6: See response to Row 5. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 41,216,110 shares of Common Stock outstanding as of December 5, 2025, as set forth in the Form 10-Q. Neotribe Ignite Fund I, L.P. ("NTIF I") b DE 1297799.00 0.00 1297799.00 0.00 1297799.00 N 3.1 PN Note to Rows 5 and 7: Neotribe Ignite Partners I, LLC ("NTIP I"), the general partner of NTIF I, may be deemed to have sole voting and dispositive power over these shares, and Kolluri, the managing member of NTIP I, may be deemed to have sole voting and dispositive power over these shares. Note to Row 6: See response to Row 5. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 41,216,110 shares of Common Stock outstanding as of December 5, 2025, as set forth in the Form 10-Q. Neotribe Ignite Partners I, LLC ("NTIP I") b DE 1297799.00 0.00 1297799.00 0.00 1297799.00 N 3.1 OO Note to Rows 5 and 7: Shares held of record by NTIF I. NTIP I, the general partner of NTIF I, may be deemed to have sole voting and dispositive power over these shares, and Kolluri, the managing member of NTIF I, may be deemed to have sole voting and dispositive power over these shares. Note to Row 6: See response to Row 5. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 41,216,110 shares of Common Stock outstanding as of December 5, 2025, as set forth in the Form 10-Q. Neotribe SPV I BTO, LLC ("NT SPV I") b DE 242216.00 0.00 242216.00 0.00 242216.00 N 0.6 OO Note to Rows 5 and 7: Neotribe Partners SPV I BTO, LLC ("NTP SPV I"), the managing member of NT SPV I, may be deemed to have sole voting and dispositive power over these shares, and Kolluri, the managing member of NTP SPV I, may be deemed to have sole voting and dispositive power over these shares. Note to Row 6: See response to Row 5. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 41,216,110 shares of Common Stock outstanding as of December 5, 2025, as set forth in the Form 10-Q. Neotribe Partners SPV I BTO, LLC ("NTP SPV I") b DE 242216.00 0.00 242216.00 0.00 242216.00 N 0.6 OO Note to Row 5: Shares held of record by NT SPV I. NTP SPV I, the managing member of NT SPV I, may be deemed to have sole voting and dispositive power over these shares, and Kolluri, the managing member of NT SPV I, may be deemed to have sole voting and dispositive power over these shares. Note to Row 6: See response to Row 5. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 41,216,110 shares of Common Stock outstanding as of December 5, 2025, as set forth in the Form 10-Q. Krishna Kittu Kolluri ("Kolluri") b X1 4359505.00 0.00 4359505.00 0.00 4359505.00 N 10.6 IN Note to Rows 5 and 7: Consists of 2,710,286 shares held of record by NTV I for itself, 109,204 shares held of record by NTV I as nominee for NTA I, 1,297,799 shares held of record by NTIF I and 242,216 shares held of record by NT SPV I. NTP I, the general partner of NTV I and NTA I, may be deemed to have sole voting and dispositive power over the shares held of record by NTV I for itself and as nominee for NTA I. NTIP I, the general partner of NTIF I, may be deemed to have sole voting and dispositive power over the shares held of record by NTIF I. NTP SPV I, the managing member of NT SPV I, may be deemed to have sole voting and dispositive power over the shares held of record by NT SPV I. Kolluri, a director of the Issuer and the managing member of NTP I, NTIP I and NTP SPV I may be deemed to have sole voting and dispositive power over the shares held of record by NTV I for itself and as nominee for NTA I, NTIF I and NT SPV I, respectively. Note to Row 6: See response to Row 5. Note to Row 8: See response to Row 7. Note to Row 11: This percentage is calculated based upon 41,216,110 shares of Common Stock outstanding as of December 5, 2025, as set forth in the Form 10-Q. BillionToOne, Inc. 1035 O'Brien Drive, Menlo Park, CA 94025 This joint statement on Schedule 13G is being filed by NeoTribe Ventures I, L.P. ("NTV I"), NeoTribe Associates I, L.P. ("NTA I"), NeoTribe Partners I, LLC ("NTP I"), Neotribe Ignite Fund I, L.P. ("NTIF I"), Neotribe Ignite Partners I, LLC ("NTIP I"), Neotribe SPV I BTO, LLC ("NT SPV I"), Neotribe Partners SPV I BTO, LLC ("NTP SPV I") and Krishna Kolluri ("Kolluri"). The foregoing entities and individuals are collectively referred to as the "Reporting Persons." c/o NeoTribe Management Company, LLC 1300 El Camino Real, Suite 100 Menlo Park, CA 94025 See Row 4 of cover page for each Reporting Person. Y See Row 9 of cover page for each Reporting Person. See Row 11 of cover page for each Reporting Person. See Row 5 of cover page for each Reporting Person. See Row 6 of cover page for each Reporting Person. See Row 7 of cover page for each Reporting Person. See Row 8 of cover page for each Reporting Person. Y N Under certain circumstances set forth in the limited partnership agreements of NTV I, NTA I and NTIF I, and the limited liability company agreement of NTP I, NTIP I, NT SPV I and NTP SPV I, the partners or members, as the case may be, of each of such entities may be deemed to have the right to receive dividends from, or the proceeds from the sale of, shares of the Issuer directly or indirectly owned by each such entity of which they are a partner or member. Y Y Y Y Exhibit A: Joint Filing Agreement NeoTribe Ventures I, L.P. ("NTV I") /s/ Krishna Kolluri 02/13/2026 NeoTribe Associates I, L.P. ("NTA I") /s/ Krishna Kolluri 02/13/2026 NeoTribe Partners I, LLC ("NTP I") /s/ Krishna Kolluri 02/13/2026 Neotribe Ignite Fund I, L.P. ("NTIF I") /s/ Krishna Kolluri 02/13/2026 Neotribe Ignite Partners I, LLC ("NTIP I") /s/ Krishna Kolluri 02/13/2026 Neotribe SPV I BTO, LLC ("NT SPV I") /s/ Krishna Kolluri 02/13/2026 Neotribe Partners SPV I BTO, LLC ("NTP SPV I") /s/ Krishna Kolluri 02/13/2026 Krishna Kittu Kolluri ("Kolluri") /s/ Krishna Kolluri 02/13/2026