organization · Reporting owner
Westlake BioPartners GP II, LLC
Disclosed activity across 3 companies
Sign in to followReported relationships
Latest disclosed role at each company.
| Company | Last reported as | Report date | Published |
|---|---|---|---|
| ACELYRIN, Inc.SLRN · Entity 79310 | 10% owner | May 09, 2023 | May 11, 2023 |
| Electra Therapeutics, Inc.ETRA · Entity 9265 | 10% owner | September 21, 2026 | September 22, 2026 |
| Latigo Biotherapeutics, Inc.LTGO · Entity 4709 | 10% owner | August 10, 2026 | August 11, 2026 |
Disclosed balances
About these balances
Latest available filing per company, not a reconstructed current portfolio. Matching sequences show the last reported balance with all source rows expandable; grouping alone does not establish account ownership. Do not add unresolved positions together. Filings may omit unchanged positions, and amendments may correct only part of an older disclosure. Jointly reported shares are not necessarily this owner's personal holdings.
ACELYRIN, Inc.
Report date May 09, 2023 · Filed May 11, 2023
Jointly reported with Westlake BioPartners Fund II, L.P., Harper Sean E
| Security / award | Ownership account | Disclosed shares / units | Disclosure context |
|---|---|---|---|
| Common StockSEC Table I · non-derivative | Direct | 9,790,729 |
Last balance in matching sequence
After 2023-05-09 transaction · row 2
Source-order balances reconcile. Account continuity and personal attribution are not independently verified.
2 source rowsRow 1 · 2023-05-09 · Conversion · Acquired 8,540,729 · Balance 8,540,729 F1: Represents shares of Common Stock received upon conversion of shares of the reported series of preferred stock on a one-for-one basis without payment of further consideration. F2: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any. F3: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose. Row 2 · 2023-05-09 · Purchase · Acquired 1,250,000 · Balance 9,790,729 F4: Represents shares of Common Stock purchased in the Issuer's initial public offering of Common Stock (the "IPO"). F2: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any. F3: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose. |
| Series A Redeemable Convertible Preferred StockSEC Table II · derivative / convertible security | Direct | 0 |
Reported balance
After 2023-05-09 transaction · row 3
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 3 · 2023-05-09 · Conversion · Disposed 4,056,795 · Balance 0 F5: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F6: Each share of Class A Common Stock was reclassified into one share of Common Stock immediately prior to the completion of the IPO. F2: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any. F3: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose. |
| Series B Redeemable Convertible Preferred StockSEC Table II · derivative / convertible security | Direct | 0 |
Reported balance
After 2023-05-09 transaction · row 4
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 4 · 2023-05-09 · Conversion · Disposed 2,445,786 · Balance 0 F5: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F6: Each share of Class A Common Stock was reclassified into one share of Common Stock immediately prior to the completion of the IPO. F2: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any. F3: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose. |
| Series C Redeemable Convertible Preferred StockSEC Table II · derivative / convertible security | Direct | 0 |
Reported balance
After 2023-05-09 transaction · row 5
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 5 · 2023-05-09 · Conversion · Disposed 2,038,148 · Balance 0 F5: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F6: Each share of Class A Common Stock was reclassified into one share of Common Stock immediately prior to the completion of the IPO. F2: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any. F3: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose. |
Filing footnotes · ownership attribution and instrument terms
F1: Represents shares of Common Stock received upon conversion of shares of the reported series of preferred stock on a one-for-one basis without payment of further consideration.
F2: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any.
F3: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose.
F4: Represents shares of Common Stock purchased in the Issuer's initial public offering of Common Stock (the "IPO").
F5: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock.
F6: Each share of Class A Common Stock was reclassified into one share of Common Stock immediately prior to the completion of the IPO.
Electra Therapeutics, Inc.
Report date September 21, 2026 · Filed September 22, 2026
Jointly reported with Westlake BioPartners Fund I, L.P., Westlake BioPartners GP I, LLC, Westlake BioPartners Fund II, L.P.
| Security / award | Ownership account | Disclosed shares / units | Disclosure context |
|---|---|---|---|
| Common StockSEC Table I · non-derivative | IndirectSee footnote | 3,527,136 |
Reported balance
Holding disclosure · report date 2026-09-21 · row 1
Holding and transaction disclosures are not merged.
1 source rowRow 1 · Balance 3,527,136 F3: Shares acquired upon the automatic conversion of redeemable preferred stock on a 1:1 basis upon the closing of the Issuer's initial public offering without the payment of further consideration. Each Reporting Person had previously waived its right to voluntarily convert such redeemable preferred stock. F1: Shares held directly by Westlake BioPartners Fund I, L.P. (Fund I). The general partner of Fund I is Westlake BioPartners GP I, LLC (GP I). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg (Seidenberg) is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Common StockSEC Table I · non-derivative | IndirectSee footnote | 2,820,403 |
Reported balance
Holding disclosure · report date 2026-09-21 · row 2
Holding and transaction disclosures are not merged.
1 source rowRow 2 · Balance 2,820,403 F3: Shares acquired upon the automatic conversion of redeemable preferred stock on a 1:1 basis upon the closing of the Issuer's initial public offering without the payment of further consideration. Each Reporting Person had previously waived its right to voluntarily convert such redeemable preferred stock. F2: Shares held directly by Westlake BioPartners Fund II, L.P. (Fund II). The general partner of Fund II is Westlake BioPartners GP II, LLC (GP II). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
Filing footnotes · ownership attribution and instrument terms
F1: Shares held directly by Westlake BioPartners Fund I, L.P. (Fund I). The general partner of Fund I is Westlake BioPartners GP I, LLC (GP I). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg (Seidenberg) is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose.
F2: Shares held directly by Westlake BioPartners Fund II, L.P. (Fund II). The general partner of Fund II is Westlake BioPartners GP II, LLC (GP II). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose.
F3: Shares acquired upon the automatic conversion of redeemable preferred stock on a 1:1 basis upon the closing of the Issuer's initial public offering without the payment of further consideration. Each Reporting Person had previously waived its right to voluntarily convert such redeemable preferred stock.
Latigo Biotherapeutics, Inc.
Report date August 10, 2026 · Filed August 11, 2026
Jointly reported with Westlake BioPartners Fund I, L.P., Westlake BioPartners GP I, LLC, Westlake BioPartners Fund II, L.P., Westlake BioPartners Opportunity Fund I, L.P., Westlake BioPartners Opportunity GP I, LLC
| Security / award | Ownership account | Disclosed shares / units | Disclosure context |
|---|---|---|---|
| Common StockSEC Table I · non-derivative | IndirectSee footnote | 1,368,532 |
Reported balance
After 2026-08-10 transaction · row 1
Joint disclosure: continuity of the reported position is unresolved; see ownership footnotes.
1 source rowRow 1 · 2026-08-10 · Conversion · Acquired 938,979 · Balance 1,368,532 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Common StockSEC Table I · non-derivative | IndirectSee footnote | 4,916,374 |
Reported balance
After 2026-08-10 transaction · row 2
Joint disclosure: continuity of the reported position is unresolved; see ownership footnotes.
1 source rowRow 2 · 2026-08-10 · Conversion · Acquired 3,547,842 · Balance 4,916,374 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Common StockSEC Table I · non-derivative | IndirectSee footnote | 5,944,009 |
Reported balance
After 2026-08-10 transaction · row 3
Joint disclosure: continuity of the reported position is unresolved; see ownership footnotes.
1 source rowRow 3 · 2026-08-10 · Conversion · Acquired 1,027,635 · Balance 5,944,009 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Common StockSEC Table I · non-derivative | IndirectSee footnote | 3,510,927 |
Reported balance
After 2026-08-10 transaction · row 4
Joint disclosure: continuity of the reported position is unresolved; see ownership footnotes.
1 source rowRow 4 · 2026-08-10 · Conversion · Acquired 3,464,072 · Balance 3,510,927 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F3: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Common StockSEC Table I · non-derivative | IndirectSee footnote | 4,995,328 |
Reported balance
After 2026-08-10 transaction · row 5
Joint disclosure: continuity of the reported position is unresolved; see ownership footnotes.
1 source rowRow 5 · 2026-08-10 · Conversion · Acquired 1,484,401 · Balance 4,995,328 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F3: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Common StockSEC Table I · non-derivative | IndirectSee footnote | 5,160,847 |
Reported balance
After 2026-08-10 transaction · row 6
Joint disclosure: continuity of the reported position is unresolved; see ownership footnotes.
1 source rowRow 6 · 2026-08-10 · Conversion · Acquired 165,519 · Balance 5,160,847 F4: Reflects a convertible note that was convertible into shares of Common Stock of the Issuer. The convertible note had a maturity date of June 17, 2027. The principal amount of the convertible note together with any accrued but unpaid interest automatically converted into shares of Common Stock of the Issuer upon the closing of the Issuer's initial public offering at a conversion price equal to the initial public offering price of the Issuer's common stock. F3: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Common StockSEC Table I · non-derivative | IndirectSee footnote | 2,094,813 |
Reported balance
After 2026-08-10 transaction · row 7
Joint disclosure: continuity of the reported position is unresolved; see ownership footnotes.
1 source rowRow 7 · 2026-08-10 · Conversion · Acquired 2,066,857 · Balance 2,094,813 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F5: Shares held directly by Westlake BioPartners Opportunity Fund I, L.P. ("Opportunity Fund"). The general partner of Opportunity Fund is Westlake BioPartners Opportunity GP I, LLC ("Opportunity GP"). Opportunity GP may be deemed to share voting and dispositive power with regard to the shares held directly by Opportunity Fund. Seidenberg is the sole managing director of Opportunity GP and has voting and dispositive power over the shares held by Opportunity Fund. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Series Seed Convertible Preferred StockSEC Table II · derivative / convertible security | IndirectSee footnote | 0 |
Reported balance
After 2026-08-10 transaction · row 8
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 8 · 2026-08-10 · Conversion · Disposed 938,979 · Balance 0 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Series A Convertible Preferred StockSEC Table II · derivative / convertible security | IndirectSee footnote | 0 |
Reported balance
After 2026-08-10 transaction · row 9
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 9 · 2026-08-10 · Conversion · Disposed 3,547,842 · Balance 0 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Series A-2 Convertible Preferred StockSEC Table II · derivative / convertible security | IndirectSee footnote | 0 |
Reported balance
After 2026-08-10 transaction · row 10
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 10 · 2026-08-10 · Conversion · Disposed 1,027,635 · Balance 0 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Series A-2 Convertible Preferred StockSEC Table II · derivative / convertible security | IndirectSee footnote | 0 |
Reported balance
After 2026-08-10 transaction · row 11
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 11 · 2026-08-10 · Conversion · Disposed 3,464,072 · Balance 0 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F3: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Series A-2 Convertible Preferred StockSEC Table II · derivative / convertible security | IndirectSee footnote | 0 |
Reported balance
After 2026-08-10 transaction · row 13
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 13 · 2026-08-10 · Conversion · Disposed 2,066,857 · Balance 0 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F5: Shares held directly by Westlake BioPartners Opportunity Fund I, L.P. ("Opportunity Fund"). The general partner of Opportunity Fund is Westlake BioPartners Opportunity GP I, LLC ("Opportunity GP"). Opportunity GP may be deemed to share voting and dispositive power with regard to the shares held directly by Opportunity Fund. Seidenberg is the sole managing director of Opportunity GP and has voting and dispositive power over the shares held by Opportunity Fund. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Series B Convertible Preferred StockSEC Table II · derivative / convertible security | IndirectSee footnote | 0 |
Reported balance
After 2026-08-10 transaction · row 12
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 12 · 2026-08-10 · Conversion · Disposed 1,484,401 · Balance 0 F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F3: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
| Convertible Promissory NoteSEC Table II · derivative / convertible security | IndirectSee footnote | 0 |
Reported balance
After 2026-08-10 transaction · row 14
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 14 · 2026-08-10 · Conversion · Disposed 165,519 · Balance 0 F4: Reflects a convertible note that was convertible into shares of Common Stock of the Issuer. The convertible note had a maturity date of June 17, 2027. The principal amount of the convertible note together with any accrued but unpaid interest automatically converted into shares of Common Stock of the Issuer upon the closing of the Issuer's initial public offering at a conversion price equal to the initial public offering price of the Issuer's common stock. F3: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. |
Filing footnotes · ownership attribution and instrument terms
F1: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.
F2: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose.
F3: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose.
F4: Reflects a convertible note that was convertible into shares of Common Stock of the Issuer. The convertible note had a maturity date of June 17, 2027. The principal amount of the convertible note together with any accrued but unpaid interest automatically converted into shares of Common Stock of the Issuer upon the closing of the Issuer's initial public offering at a conversion price equal to the initial public offering price of the Issuer's common stock.
F5: Shares held directly by Westlake BioPartners Opportunity Fund I, L.P. ("Opportunity Fund"). The general partner of Opportunity Fund is Westlake BioPartners Opportunity GP I, LLC ("Opportunity GP"). Opportunity GP may be deemed to share voting and dispositive power with regard to the shares held directly by Opportunity Fund. Seidenberg is the sole managing director of Opportunity GP and has voting and dispositive power over the shares held by Opportunity Fund. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose.
Transaction history
JSON APIPurchases/sales include open-market and private transactions. Plan disclosure applies to the filing; individual rows may differ. “Not disclosed” is not “unplanned.”
The cutoff filters transaction history only. Company summaries and owner relationships show the latest available disclosures. Parser corrections can improve historical records.
| Transaction date | Company | Activity / security | Shares / units | Reported price | Reported value | Details |
|---|---|---|---|---|---|---|
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionConvertible Promissory Note · Derivative | 165,519 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · derivative · entry 14 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 0 Underlying: Common Stock · 165,519 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F4 · derivative.exercise_price: Reflects a convertible note that was convertible into shares of Common Stock of the Issuer. The convertible note had a maturity date of June 17, 2027. The principal amount of the convertible note together with any accrued but unpaid interest automatically converted into shares of Common Stock of the Issuer upon the closing of the Issuer's initial public offering at a conversion price equal to the initial public offering price of the Issuer's common stock. F4 · price: Reflects a convertible note that was convertible into shares of Common Stock of the Issuer. The convertible note had a maturity date of June 17, 2027. The principal amount of the convertible note together with any accrued but unpaid interest automatically converted into shares of Common Stock of the Issuer upon the closing of the Issuer's initial public offering at a conversion price equal to the initial public offering price of the Issuer's common stock. F4 · derivative.exercise_date: Reflects a convertible note that was convertible into shares of Common Stock of the Issuer. The convertible note had a maturity date of June 17, 2027. The principal amount of the convertible note together with any accrued but unpaid interest automatically converted into shares of Common Stock of the Issuer upon the closing of the Issuer's initial public offering at a conversion price equal to the initial public offering price of the Issuer's common stock. F4 · derivative.expiration_date: Reflects a convertible note that was convertible into shares of Common Stock of the Issuer. The convertible note had a maturity date of June 17, 2027. The principal amount of the convertible note together with any accrued but unpaid interest automatically converted into shares of Common Stock of the Issuer upon the closing of the Issuer's initial public offering at a conversion price equal to the initial public offering price of the Issuer's common stock. F3 · ownership.nature: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionSeries A-2 Convertible Preferred Stock · Derivative | 2,066,857 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · derivative · entry 13 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 0 Underlying: Common Stock · 2,066,857 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.exercise_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.expiration_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F5 · ownership.nature: Shares held directly by Westlake BioPartners Opportunity Fund I, L.P. ("Opportunity Fund"). The general partner of Opportunity Fund is Westlake BioPartners Opportunity GP I, LLC ("Opportunity GP"). Opportunity GP may be deemed to share voting and dispositive power with regard to the shares held directly by Opportunity Fund. Seidenberg is the sole managing director of Opportunity GP and has voting and dispositive power over the shares held by Opportunity Fund. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionSeries B Convertible Preferred Stock · Derivative | 1,484,401 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · derivative · entry 12 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 0 Underlying: Common Stock · 1,484,401 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.exercise_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.expiration_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F3 · ownership.nature: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionSeries A-2 Convertible Preferred Stock · Derivative | 3,464,072 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · derivative · entry 11 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 0 Underlying: Common Stock · 3,464,072 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.exercise_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.expiration_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F3 · ownership.nature: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionSeries A-2 Convertible Preferred Stock · Derivative | 1,027,635 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · derivative · entry 10 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 0 Underlying: Common Stock · 1,027,635 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.exercise_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.expiration_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2 · ownership.nature: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionSeries A Convertible Preferred Stock · Derivative | 3,547,842 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · derivative · entry 9 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 0 Underlying: Common Stock · 3,547,842 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.exercise_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.expiration_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2 · ownership.nature: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionSeries Seed Convertible Preferred Stock · Derivative | 938,979 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · derivative · entry 8 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 0 Underlying: Common Stock · 938,979 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.exercise_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F1 · derivative.expiration_date: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2 · ownership.nature: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionCommon Stock | 2,066,857 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · nonDerivative · entry 7 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 2,094,813 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F5 · ownership.nature: Shares held directly by Westlake BioPartners Opportunity Fund I, L.P. ("Opportunity Fund"). The general partner of Opportunity Fund is Westlake BioPartners Opportunity GP I, LLC ("Opportunity GP"). Opportunity GP may be deemed to share voting and dispositive power with regard to the shares held directly by Opportunity Fund. Seidenberg is the sole managing director of Opportunity GP and has voting and dispositive power over the shares held by Opportunity Fund. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionCommon Stock | 165,519 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · nonDerivative · entry 6 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 5,160,847 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F4 · price: Reflects a convertible note that was convertible into shares of Common Stock of the Issuer. The convertible note had a maturity date of June 17, 2027. The principal amount of the convertible note together with any accrued but unpaid interest automatically converted into shares of Common Stock of the Issuer upon the closing of the Issuer's initial public offering at a conversion price equal to the initial public offering price of the Issuer's common stock. F3 · ownership.nature: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionCommon Stock | 1,484,401 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · nonDerivative · entry 5 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 4,995,328 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F3 · ownership.nature: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionCommon Stock | 3,464,072 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · nonDerivative · entry 4 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 3,510,927 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F3 · ownership.nature: Shares held directly by Westlake BioPartners Fund II, L.P. ("Fund II"). The general partner of Fund II is Westlake BioPartners GP II, LLC ("GP II"). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. Seidenberg is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionCommon Stock | 1,027,635 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · nonDerivative · entry 3 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 5,944,009 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2 · ownership.nature: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionCommon Stock | 3,547,842 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · nonDerivative · entry 2 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 4,916,374 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2 · ownership.nature: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| August 10, 2026 Filed Aug 11, 2026 10:00 UTC | Latigo Biotherapeutics, Inc. LTGO · Entity 4709 | ConversionCommon Stock | 938,979 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001104659-26-093633 · tm2622668-1_4seq1.xml · nonDerivative · entry 1 Westlake BioPartners Fund I, L.P. · CIK 0001749591 · 10% owner Westlake BioPartners GP I, LLC · CIK 0002007650 · 10% owner Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Westlake BioPartners Opportunity Fund I, L.P. · CIK 0001811946 · 10% owner Westlake BioPartners Opportunity GP I, LLC · CIK 0001811945 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 1,368,532 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date. F2 · ownership.nature: Shares held directly by Westlake BioPartners Fund I, L.P. ("Fund I"). The general partner of Fund I is Westlake BioPartners GP I, LLC ("GP I"). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. Beth Seidenberg ("Seidenberg") is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. Seidenberg disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose. Read SEC document |
| May 09, 2023 Filed May 11, 2023 21:16 UTC | ACELYRIN, Inc. SLRN · Entity 79310 | ConversionSeries C Redeemable Convertible Preferred Stock · Derivative | 2,038,148 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001209191-23-028886 · doc4.xml · derivative · entry 5 Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Harper Sean E · CIK 0001541946 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 0 Underlying: Common Stock · 2,038,148 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F5 · derivative.exercise_price: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F5 · price: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F5 · derivative.exercise_date: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F5 · derivative.expiration_date: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F6 · derivative.underlying: Each share of Class A Common Stock was reclassified into one share of Common Stock immediately prior to the completion of the IPO. F2 · ownership.direct: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any. F3 · ownership.direct: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose. Read SEC document |
| May 09, 2023 Filed May 11, 2023 21:16 UTC | ACELYRIN, Inc. SLRN · Entity 79310 | ConversionSeries B Redeemable Convertible Preferred Stock · Derivative | 2,445,786 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001209191-23-028886 · doc4.xml · derivative · entry 4 Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Harper Sean E · CIK 0001541946 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 0 Underlying: Common Stock · 2,445,786 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F5 · derivative.exercise_price: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F5 · price: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F5 · derivative.exercise_date: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F5 · derivative.expiration_date: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F6 · derivative.underlying: Each share of Class A Common Stock was reclassified into one share of Common Stock immediately prior to the completion of the IPO. F2 · ownership.direct: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any. F3 · ownership.direct: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose. Read SEC document |
| May 09, 2023 Filed May 11, 2023 21:16 UTC | ACELYRIN, Inc. SLRN · Entity 79310 | ConversionSeries A Redeemable Convertible Preferred Stock · Derivative | 4,056,795 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001209191-23-028886 · doc4.xml · derivative · entry 3 Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Harper Sean E · CIK 0001541946 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 0 Underlying: Common Stock · 4,056,795 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F5 · derivative.exercise_price: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F5 · price: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F5 · derivative.exercise_date: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F5 · derivative.expiration_date: Each share of preferred stock is convertible into one share of Common Stock and has no expiration date. Immediately prior to the completion of the IPO, all shares of preferred stock automatically converted into shares of Common Stock. F6 · derivative.underlying: Each share of Class A Common Stock was reclassified into one share of Common Stock immediately prior to the completion of the IPO. F2 · ownership.direct: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any. F3 · ownership.direct: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose. Read SEC document |
| May 09, 2023 Filed May 11, 2023 21:16 UTC | ACELYRIN, Inc. SLRN · Entity 79310 | PurchaseCommon Stock | 1,250,000 | $18.00 | $22,500,000.00 |
DisclosureSEC source: 0001209191-23-028886 · doc4.xml · nonDerivative · entry 2 Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Harper Sean E · CIK 0001541946 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 9,790,729 F4 · kind: Represents shares of Common Stock purchased in the Issuer's initial public offering of Common Stock (the "IPO"). F2 · ownership.direct: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any. F3 · ownership.direct: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose. Read SEC document |
| May 09, 2023 Filed May 11, 2023 21:16 UTC | ACELYRIN, Inc. SLRN · Entity 79310 | ConversionCommon Stock | 8,540,729 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001209191-23-028886 · doc4.xml · nonDerivative · entry 1 Westlake BioPartners Fund II, L.P. · CIK 0001811947 · 10% owner Westlake BioPartners GP II, LLC · CIK 0001811948 · 10% owner Harper Sean E · CIK 0001541946 · 10% owner Joint disclosure: these amounts are not allocated separately to each reporting owner. 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 8,540,729 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: Represents shares of Common Stock received upon conversion of shares of the reported series of preferred stock on a one-for-one basis without payment of further consideration. F1 · price: Represents shares of Common Stock received upon conversion of shares of the reported series of preferred stock on a one-for-one basis without payment of further consideration. F2 · ownership.direct: Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any. F3 · ownership.direct: This report on Form 4 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose. Read SEC document |
Value uses the disclosed total when available, otherwise shares × reported transaction price. It is not an estimate of exercise cash cost or investment performance.