MACK
MERRIMACK PHARMACEUTICALS INC
Total Trades
50
Buys
49
Sells
1
Largest Trade
$1M+
Insiders
6
Institutional Funds
1
Inst. Value
N/A
Activist Filings
10
Insider Trades
| Insider | Title | Type | Value | Shares | Price | Date |
|---|---|---|---|---|---|---|
| Andersen Eric | Director | BUY | $500K+ | 50K | $13.15 | Dec 28, 2023 |
| Andersen Eric | Director | BUY | $1K–$15K | 300 | $12.50 | Nov 20, 2023 |
| Andersen Eric | Director | BUY | $500K+ | 50K | $12.50 | Nov 16, 2023 |
| Andersen Eric | Director | BUY | $500K+ | 54K | $12.34 | Nov 14, 2023 |
| Andersen Eric | Director | BUY | $100K–$500K | 24K | $12.16 | Nov 13, 2023 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 4K | $12.48 | Aug 14, 2023 |
| Andersen Eric | Director | BUY | $1M+ | 222K | $12.00 | Aug 9, 2023 |
| Andersen Eric | Director | BUY | $1M+ | 161K | $11.52 | Mar 22, 2023 |
| Andersen Eric | Director | BUY | $100K–$500K | 27K | $11.36 | Feb 1, 2023 |
| Andersen Eric | Director | BUY | $100K–$500K | 22K | $11.40 | Jan 31, 2023 |
| Levy Noah G. | Director | BUY | $1M+ | 100K | $11.90 | Jan 17, 2023 |
| Radeljevic Ana | Director | BUY | $15K–$50K | 4K | $12.03 | Jan 9, 2023 |
| Levy Noah G. | Director | BUY | $50K–$100K | 7K | $11.24 | Jan 4, 2023 |
| Andersen Eric | Director | BUY | $100K–$500K | 31K | $11.33 | Jan 4, 2023 |
| Andersen Eric | Director | BUY | $1M+ | 260K | $10.67 | Jan 3, 2023 |
| Levy Noah G. | Director | BUY | $15K–$50K | 3K | $5.89 | Jul 15, 2022 |
| Levy Noah G. | Director | BUY | $15K–$50K | 4K | $5.89 | Jul 13, 2022 |
| Levy Noah G. | Director | BUY | $1K–$15K | 2K | $5.99 | Jul 11, 2022 |
| Levy Noah G. | Director | BUY | $1K–$15K | 2K | $5.76 | Jul 5, 2022 |
| Levy Noah G. | Director | BUY | $1K–$15K | 2K | $5.99 | Jun 27, 2022 |
| Levy Noah G. | Director | BUY | $1K–$15K | 1K | $5.78 | Jun 21, 2022 |
| Levy Noah G. | Director | BUY | $100K–$500K | 24K | $5.20 | Jun 16, 2022 |
| Levy Noah G. | Director | BUY | $50K–$100K | 16K | $5.06 | Jun 14, 2022 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 4K | $5.15 | Jun 13, 2022 |
| CROCKER GARY L | See Remarks | BUY | $1K–$15K | 649 | $5.10 | Jun 9, 2022 |
| CROCKER GARY L | See Remarks | BUY | $1K–$15K | 2K | $5.09 | May 26, 2022 |
| CROCKER GARY L | See Remarks | BUY | $1K–$15K | 512 | $5.04 | May 23, 2022 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 5K | $5.08 | May 19, 2022 |
| CROCKER GARY L | See Remarks | BUY | $1K–$15K | 2K | $5.04 | May 16, 2022 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 5K | $6.00 | Apr 25, 2022 |
| CROCKER GARY L | See Remarks | BUY | $1K–$15K | 461 | $6.18 | Apr 1, 2022 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 5K | $6.16 | Mar 29, 2022 |
| CROCKER GARY L | See Remarks | BUY | $1K–$15K | 400 | $6.11 | Mar 24, 2022 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 5K | $6.14 | Mar 17, 2022 |
| CROCKER GARY L | See Remarks | BUY | $50K–$100K | 10K | $6.05 | Mar 15, 2022 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 3K | $5.96 | Feb 23, 2022 |
| CROCKER GARY L | See Remarks | BUY | $50K–$100K | 13K | $6.17 | Feb 18, 2022 |
| CROCKER GARY L | See Remarks | BUY | $1K–$15K | 2K | $5.97 | Feb 16, 2022 |
| Levy Noah G. | Director | BUY | $50K–$100K | 14K | $4.53 | Feb 1, 2022 |
| CROCKER GARY L | See Remarks | BUY | $1K–$15K | 673 | $4.60 | Jan 31, 2022 |
| Levy Noah G. | Director | BUY | $100K–$500K | 36K | $4.92 | Jan 28, 2022 |
| CROCKER GARY L | See Remarks | BUY | $1K–$15K | 3K | $4.56 | Jan 27, 2022 |
| Nielsen Ulrik B. | Director | BUY | $50K–$100K | 14K | $4.24 | Jan 25, 2022 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 9K | $4.40 | Jan 25, 2022 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 5K | $4.54 | Jan 20, 2022 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 10K | $4.47 | Jan 18, 2022 |
| CROCKER GARY L | See Remarks | BUY | $15K–$50K | 10K | $4.18 | Jan 13, 2022 |
| Levy Noah G. | Director | BUY | $100K–$500K | 106K | $3.98 | Jan 12, 2022 |
| Levy Noah G. | Director | BUY | $15K–$50K | 9K | $3.82 | Jan 10, 2022 |
| RAY RUSSELL T | Director | SELL | $1K–$15K | 1K | $3.84 | Jan 4, 2022 |
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Institutional Ownership
13F filings as of Dec 31, 2025 · 1 funds holding
| Fund | Shares | Value | Type |
|---|---|---|---|
| MassMutual Private Wealth & Trust, FSB | 25K | N/A | SH |
Activist & 5%+ Owners
SC 13D/13G filings — investors holding 5%+ of outstanding shares
SC 13G/A · Mar 7, 2024
5.0%
715K shares
SC 13G · Feb 22, 2024
6.3%
902K shares
SC 13G/A · Feb 14, 2024
0.0%
0 shares
SC 13G · Jan 31, 2024
5.2%
744K shares
SC 13D/A · Jan 25, 2024
13.1%
1.9M shares
Western Standard, LLC 26-2921385
SC 13D/A · Dec 13, 2023
15.5%
2.2M shares
Western Standard, LLC 26-2921385
SC 13D/A · Aug 14, 2023
13.9%
2.0M shares
SC 13G/A · Feb 13, 2023
7.6%
1.0M shares
SC 13G/A · Feb 14, 2022
9.3%
1.2M shares
Nantahala Capital Management, LLC
SC 13G/A · Feb 14, 2022
4.3%
570K shares