Merrimack Pharmaceuticals Inc
MACKInactive ticker- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0001274792
No open-market purchases or sales by Merrimack Pharmaceuticals Inc insiders were filed in the last 90 days; 1 institution reported holding it in 13F filings for Q2 2026, worth $0 in total; no superinvestor holds it.
This ticker is no longer on the SEC's list of tickers: the company may have been delisted, or the ticker has changed.
Key figures
- Insider buys
- 0
- Open market, last 90 days
- Insider sells
- 0
- Open market, last 90 days
- 13F holders
- 1
- Q2 2026, 0 vs. previous quarter
- 13F value
- $0
- Reported value at the end of Q2 2026
- Superinvestors holding
- 0
- At the end of Q2 2026
Superinvestors holding MACK, Q2 2026
No superinvestor reported holding MACK at the end of Q2 2026.
Latest insider trades
Open-market purchases and sales by Merrimack Pharmaceuticals Inc insiders from Form 4, newest first.
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Dec 28, 2023 (view filing)4:05 PM ET | Dec 26-28 | 2 days | Andersen Eric and 3 othersDirector, Other: See remarks | PPurchase | +49.5K | $13.15 | +$651.8K | +10.2%534.0K after | 2 lots |
| Dec 11, 2023 (view filing)4:05 PM ET | Dec 7 | 4 days | Andersen Eric and 3 othersDirector, Other: See remarks | PPurchase | +101.0K | $12.85 | +$1.30M | +26.4%484.5K after | 2 lots |
| Nov 20, 2023 (view filing)6:59 PM ET | Nov 17 | 3 days | Andersen Eric and 3 othersDirector, Other: See remarks | PPurchase | +300 | $12.50 | +$3.75K | +0.1%459.8K after | 2 lots |
| Nov 16, 2023 (view filing)5:09 PM ET | Nov 14 | 2 days | Andersen Eric and 3 othersDirector, Other: See remarks | PPurchase | +50.2K | $12.50 | +$627.1K | +12.2%459.7K after | 2 lots |
| Nov 14, 2023 (view filing)4:48 PM ET | Nov 10-13 | 4 days | Andersen Eric and 3 othersDirector, Other: See remarks | PPurchase | +53.6K | $12.34 | +$661.9K | +13.6%448.8K after | 4 lots |
| Nov 13, 2023 (view filing)4:05 PM ET | Nov 8-9 | 5 days | Andersen Eric and 3 othersDirector, Other: See remarks | PPurchase | +23.8K | $12.16 | +$289.3K | +5.8%437.2K after | 4 lots |
| Aug 14, 2023 (view filing) | Aug 10-11 | 4 days | Crocker Gary LSee Remarks | PPurchase | +4.00K | $12.48 | +$49.9K | +3.1%133.1K after | 2 lots |
| Aug 9, 2023 (view filing)4:06 PM ET | Aug 7-8 | 2 days | Andersen Eric and 3 othersDirector, Other: See remarks | PPurchase | +221.6K | $12.00 | +$2.66M | +108.4%426.0K after | 4 lots |
| Mar 22, 2023 (view filing)4:06 PM ET | Mar 21 | 1 day | Andersen Eric and 3 othersDirector, Other: See remarks | PPurchase | +160.6K | $11.52 | +$1.85M | +81.5%357.5K after | 2 lots |
| Mar 1, 2023 (view filing)5:04 PM ET | Jan 30-31 | 30 days | Andersen Eric and 3 othersDirector, Other: See remarks | PPurchase | +27.0K | $11.36 | +$306.4K | +9.1%324.3K after | Amended4 lots |
Top 10 13F holders, Q2 2026
The largest institutional positions in Merrimack Pharmaceuticals Inc at the end of Q2 2026; share changes are against Q1 2026.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Massmutual Trust Co FSB | 24,500 | $0 | 0.00% | 00.0% | Unchanged |