ARCH Venture Partners XII, LLC
- SEC CIK
- 0001979548
In the past year, 1 open-market purchase filing worth $19.8M and no sales.
Current role at each company
- SPTX Seaport Therapeutics, Inc.10% Owneras of May 4, 2026
- MTSR Metsera, Inc.Director, 10% Owneras of Nov 14, 2025
- NMRA Neumora Therapeutics, Inc.10% Owneras of Oct 29, 2025
- PRME Prime Medicine, Inc.10% Owneras of Aug 1, 2025
- RAPP Rapport Therapeutics, Inc.10% Owneras of Jun 10, 2024
Open-market trades in the past year
Open-market purchases (P) and sales (S) filed in the last 365 days, not counting derivative securities or duplicate filings. Values leave out price outliers.
- Bought
- $19.8M
- 1 filing
- Sold
- –
- 0 filings
- Net
- +$19.8M
- Bought minus sold
- Companies
- 1
- With open-market trades
Trades
Every Form 4 that lists ARCH Venture Partners XII, LLC as a reporting owner, including filings made jointly with others, grouped by company. Each row adds up one type of transaction in one filing. Only open-market purchases (P) and sales (S) are shown by default.
SPTX Seaport Therapeutics, Inc.
10% Owner1 trade
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| May 4, 2026 (view filing)6:02 PM ET | May 4 | Same day | Crandell Keith and 6 others10% Owner | PPurchase | +1.10M | $18.00 | +$19.8M | +21.2%6.29M after |
NMRA Neumora Therapeutics, Inc.
10% Owner8 trades
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Oct 29, 2025 (view filing)7:21 PM ET | Oct 27 | 2 days | Crandell Keith and 6 others10% Owner | PPurchase | +1.92M | $2.61 | +$5.00M | +46.4%6.05M after | Duplicate filing |
| Nov 15, 2023 (view filing)6:54 PM ET | Nov 13-14 | 2 days | Crandell Keith and 5 others10% Owner | PPurchase | +35.0K | $11.77 | +$412.1K | +0.9%4.13M after | 2 lotsDuplicate filing |
| Nov 13, 2023 (view filing)7:00 PM ET | Nov 8-10 | 5 days | Crandell Keith and 5 others10% Owner | PPurchase | +140.6K | $10.98 | +$1.54M | +3.6%4.10M after | 5 lotsDuplicate filing |
| Nov 7, 2023 (view filing)6:59 PM ET | Nov 3-7 | 4 days | Crandell Keith and 5 others10% Owner | PPurchase | +95.7K | $11.49 | +$1.10M | +2.5%3.96M after | 3 lotsDuplicate filing |
| Sep 29, 2023 (view filing)6:53 PM ET | Sep 28-29 | 1 day | Crandell Keith and 5 others10% Owner | PPurchase | +76.5K | $13.68 | +$1.05M | +2.0%3.86M after | 3 lotsDuplicate filing |
| Sep 27, 2023 (view filing)8:18 PM ET | Sep 26-27 | 1 day | Crandell Keith and 5 others10% Owner | PPurchase | +58.5K | $11.97 | +$700.5K | +1.6%3.78M after | 2 lotsDuplicate filing |
| Sep 25, 2023 (view filing)9:38 PM ET | Sep 22-25 | 3 days | Crandell Keith and 5 others10% Owner | PPurchase | +100.7K | $11.19 | +$1.13M | +2.8%3.72M after | 3 lotsDuplicate filing |
| Sep 20, 2023 (view filing)6:16 AM ET | Sep 19 | 1 day | Crandell Keith and 7 others10% Owner | PPurchase | +1.50M | $17.00 | +$25.5M | +70.6%3.62M after | Duplicate filing |
PRME Prime Medicine, Inc.
10% Owner2 trades
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Aug 1, 2025 (view filing)7:19 PM ET | Aug 1 | Same day | ARCH Venture Fund XII, L.P. and 2 others10% Owner | PPurchase | +3.03M | $3.30 | +$10.0M | +94.7%6.23M after | Duplicate filing |
| Feb 20, 2024 (view filing)5:38 PM ET | Feb 15 | 5 days | ARCH Venture Fund XII, L.P. and 2 others10% Owner | PPurchase | +3.20M | $6.25 | +$20.0M | New position3.20M after | Duplicate filing |
MTSR Metsera, Inc.
Director, 10% Owner1 trade
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Feb 3, 2025 (view filing)7:01 PM ET | Feb 3 | Same day | Crandell Keith and 8 others10% Owner | PPurchase | +2.22M | $18.00 | +$40.0M | +36.5%8.31M after | 2 lotsDuplicate filing |