Third Rock Ventures IV, L.P.
CIK 1688327 · last filed 2025-09-17
Third Rock Ventures IV, L.P. is a corporate insider who has filed 35 SEC Form 4 insider transactions across 5 companies since 2018. The most recent filing, for TNGX, was dated Oct 23, 2025. Across all open-market trades the lifetime net is −$2.10B, making them a net seller over the disclosed history. Current disclosed insider exposure totals $816.7M across reported positions. The firm reports its address in Boston, MA. 36 SEC filings were submitted jointly with TRV GP IV, LLC.
"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.
$816.68M
5
35
-$2.10B
Filer Profile
BOSTON, MA 02215
Holdings By Company
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| TNGX | 10%+ Owner | 14,363,975 | $22.52 | $323.48M | -$58.00M | 7 | 2025-09-17 |
| RLAY | 10%+ Owner | 9,767,382 | $19.04 | $185.97M | -$2.04B | 1 | 2021-01-14 |
| RVMD | 10%+ Owner | 1,419,900 | $210.02 | $298.21M | $0 | 1 | 2020-02-18 |
| FULC | 10%+ Owner | 2,343,154 | $3.85 | $9.02M | $3.90M | 1 | 2019-07-22 |
| Dianthus Therapeutics, Inc. /DE/ (MGTA) Delisted | 10%+ Owner | 500,513 | $11.19 | $5.60M | $0 | 1 | 2018-06-27 |
Recent Filings
35 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2025-10-23 | TNGX | Notice (144) | −477,401 | -$3.59M | EDGAR |
| 2025-09-25 | TNGX | Notice (144) | −500,000 | -$3.90M | EDGAR |
| 2025-09-17 | TNGX | Sell (S) | −1,090,623 | -$7.68M | EDGAR |
| 2025-09-17 | TNGX | Notice (144) | −363,541 | -$2.67M | EDGAR |
| 2025-09-08 | TNGX | Notice (144) | −86,459 | -$608.6K | EDGAR |
| 2025-09-05 | TNGX | Notice (144) | −642,906 | -$4.46M | EDGAR |
| 2025-08-22 | TNGX | Notice (144) | −302,194 | -$2.09M | EDGAR |
| 2025-08-19 | TNGX | Notice (144) | −1,100,000 | -$7.66M | EDGAR |
| 2024-09-13 | TNGX | Notice (144) | −67,400 | -$707.7K | EDGAR |
| 2024-09-05 | TNGX | Notice (144) | −75,000 | -$876.0K | EDGAR |
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.