Merrimack PharmaceuticalsMACK
13F holders, Q4 2024 (December 31)2holders
2new positions
2sold out
$15.12avg. 13F price*
At the end of Q4 2024, 2 institutions reported holding Merrimack Pharmaceuticals Inc. (MACK) in their 13F filings, unchanged from Q3 2024. 2 opened new positions and 2 sold out. The largest holders were MassMutual Private Wealth & Trust, FSB ($371K) and Nisa Investment Advisors, LLC ($0).
- Company
- Merrimack Pharmaceuticals Inc.
- CUSIP
- 590328209
- Latest filing quarter
- Q2 2026
History
Number of 13F holders
Total Exit/New Position Q3 2024 → Q4 2024
| Institutions | Total Value | |
|---|---|---|
| New Positions | 2 | $371K |
| Exits | 2 | $0 |
All 13F filers, Q3 2024 → Q4 2024: 24,515 shares bought and 349 shares sold, net +24,166 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.
Ownership 2 holders
| MassMutual Private Wealth & Trust, FSB | 0.01% | New | 24,500 | $371K |
| Nisa Investment Advisors, LLC | 0.00% | New | 15 | $0 |
"% of holder's portfolio" is MACK's weight in each manager's 13F, not the share of Merrimack Pharmaceuticals Inc. the manager owns.