ARCH Venture Fund XII, L.P. — SEC Form 4 filings
SEC reporting owner CIK 1906837. 7 Form 4 filings on record with FilingPulse; latest filed 2026-05-04.
Transaction summary — filings shown
Covers all 7 filings on record, filed 2024-02-20 to 2026-05-04. Counts and totals are arithmetic on values as filed — descriptive data, not a recommendation.
- Open-market purchases (code P, non-derivative): 6 legs across 5 filings — 11,468,222 shares, $94,799,963 total (shares × price as filed).
- Open-market sales (code S, non-derivative): none reported.
- Other reported legs (grants, option exercises, tax withholding, gifts, derivative-security transactions, …): 16.
- Largest priced transaction: purchase of 1,432,224 shares @ $18.00 ($25,780,032) in Metsera, Inc., filed 2025-02-03.
By issuer — same filings
Open-market purchase/sale legs on non-derivative securities, grouped by issuer. Role is as filed on the newest filing for that issuer. Dollar totals cover priced legs only (shares × price as filed). Ordered by priced transaction value, largest first.
| Issuer | Role (as filed) | Filings | Purchases (P) | Sales (S) | Other legs |
|---|---|---|---|---|---|
| Metsera, Inc. (MTSR) | Director, 10% owner | 2 | 2 legs · 2,222,222 sh · $39,999,996 | — | 9 |
| Prime Medicine, Inc. (PRME) | 10% owner | 2 | 2 legs · 6,230,300 sh · $29,999,990 | — | — |
| Seaport Therapeutics, Inc. (SPTX) | 10% owner | 1 | 1 leg · 1,100,000 sh · $19,800,000 | — | 4 |
| Neumora Therapeutics, Inc. (NMRA) | 10% owner | 1 | 1 leg · 1,915,700 sh · $4,999,977 | — | — |
| Rapport Therapeutics, Inc. (RAPP) | 10% owner | 1 | — | — | 3 |
Form 4 filings — ARCH Venture Fund XII, L.P.
| Filed | Form | Issuer | Reported transactions | Source |
|---|---|---|---|---|
| 2026-05-04 | 4 | Seaport Therapeutics, Inc. (SPTX) jointly with ARCH Venture Partners XII, LLC, ARCH Venture Partners XII, L.P., CRANDELL KEITH, NELSEN ROBERT, Burow Kristina, GILLIS STEVEN | Conversion (C): 2,513,686 · Conversion (C): 2,681,265 · Purchase (P): 1,100,000 @ $18 · Conversion (C): 2,513,686 (derivative) @ $0 · Conversion (C): 2,681,265 (derivative) @ $0 | EDGAR |
| 2025-11-14 | 4 | Metsera, Inc. (MTSR) jointly with ARCH Venture Partners XII, LLC, ARCH Venture Partners XII, L.P., ARCH Venture Fund XIII, L.P., ARCH Venture Partners XIII, L.P., ARCH Venture Partners XIII, LLC, CRANDELL KEITH, GILLIS STEVEN, NELSEN ROBERT | Disposition to issuer (D): 18,503,128 · Disposition to issuer (D): 8,313,680 | EDGAR |
| 2025-10-29 | 4 | Neumora Therapeutics, Inc. (NMRA) jointly with ARCH Venture Partners XII, LLC, ARCH Venture Partners XII, L.P., CRANDELL KEITH, GILLIS STEVEN, NELSEN ROBERT, BYBEE CLINTON | Purchase (P): 1,915,700 @ $2.61 | EDGAR |
| 2025-08-01 | 4 | Prime Medicine, Inc. (PRME) jointly with ARCH Venture Partners XII, LLC, ARCH Venture Partners XII, L.P. | Purchase (P): 3,030,300 @ $3.30 | EDGAR |
| 2025-02-03 | 4 | Metsera, Inc. (MTSR) jointly with ARCH Venture Partners XII, LLC, ARCH Venture Partners XII, L.P., ARCH Venture Fund XIII, L.P., ARCH Venture Partners XIII, L.P., ARCH Venture Partners XIII, LLC, CRANDELL KEITH, GILLIS STEVEN, NELSEN ROBERT | Conversion (C): 16,006,949 · Conversion (C): 7,523,682 · Purchase (P): 1,432,224 @ $18 · Purchase (P): 789,998 @ $18 · Conversion (C): 19,933,333 (derivative) · Conversion (C): 15,000,000 (derivative) · +3 more | EDGAR |
| 2024-06-10 | 4 | Rapport Therapeutics, Inc. (RAPP) jointly with ARCH Venture Partners XII, LLC, ARCH Venture Partners XII, L.P., CRANDELL KEITH, NELSEN ROBERT, Burow Kristina, GILLIS STEVEN | Conversion (C): 3,728,738 @ $0 · Conversion (C): 20,000,000 (derivative) @ $0 · Conversion (C): 11,924,138 (derivative) @ $0 | EDGAR |
| 2024-02-20 | 4 | Prime Medicine, Inc. (PRME) jointly with ARCH Venture Partners XII, LLC, ARCH Venture Partners XII, L.P. | Purchase (P): 3,200,000 @ $6.25 | EDGAR |
FilingPulse's Form 4 archive currently extends back to 2024-01-11 and is expanding backward through EDGAR history — earlier filings by this insider may not be indexed yet. Names and roles are shown as filed.
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