Holder evidence
50
SEC ownership of Immuneering Corp
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001790340.
Lead holder
FMR LLC
13D/G signal
FMR LLC
Latest evidence
31 Mar 2026
- CIK
- 0001790340
- Symbol
- IMRX on Nasdaq
- Location
- Cambridge, MA
- SEC evidence mix
- 13D/G, 13F, and 3/4/5
- Lead holder
- FMR LLC
- Latest large-stake holder
- FMR LLC
- Latest evidence date
- 31 Mar 2026
Issuer identity
Ownership snapshot
Ownership snapshot
Top shareholders of Immuneering Corp (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Lead holder
FMR LLC
13D/G signal
FMR LLC
Evidence rows
50
Latest as of
31 Mar 2026
13D/G
13F
3/4/5
Lead comparable stake: 14%
13D/G row: FMR LLC
Showing 1-8 of 50 holder rows.
Rank 1 holder
FMR LLC
13D/G
13F
- Ownership
- 14%
- Position
- $71.53M
Rank 2 holder
Benjamin J. Zeskind
13D/G
3/4/5
- Ownership
- 6.6%
- Position
- $28.67M
Rank 3 holder
HBM Healthcare Investments (Cayman) Ltd.
13D/G
- Ownership
- 5.7%
- Position
- $29.68M
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| FMR LLC |
13D/G
13F
Company
|
14%
|
$71,526,603
8,787,052 shares
|
$0 | 30 Sep 2025 |
| Benjamin J. Zeskind |
13D/G
3/4/5
PRESIDENT AND CEO, Director
|
6.6%
|
$28,674,370
4,357,807 shares
|
+$2,498,025 | 31 Dec 2025 |
| HBM Healthcare Investments (Cayman) Ltd. |
13D/G
|
5.7%
|
$29,680,915
3,646,304 shares
|
$0 | 26 Sep 2025 |
| Empery Asset Management, LP |
13D/G
|
5%
|
$20,154,805
3,250,775 shares
|
-$12,015,476 | 31 Dec 2025 |
| Sanofi |
13F
Company
|
4.1%
|
$14,274,106
2,708,559 shares
|
— | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
Company
|
3.5%
|
$12,059,557
2,288,341 shares
|
— | 31 Mar 2026 |
| MARSHALL WACE, LLP |
13F
Company
|
3%
|
$10,522,002
1,996,585 shares
|
— | 31 Mar 2026 |
| PRICE T ROWE ASSOCIATES INC /MD/ |
13F
Company
|
2.8%
|
$9,640,000
1,829,188 shares
|
— | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to buying over the last 12 months. Net value: +$721,042.
Buys
$721,042
Insiders: 9
Sells
$0
Insiders: 0
Net
+$721,042
Shares: +201,446
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 201,446
Shares: 0
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 0 | $0 | $0 | $0 |
| 3-6 | 51,819 | 0 | $234,343 | $0 | +$234,343 |
| 6-9 | 22,120 | 0 | $152,642 | $0 | +$152,642 |
| 9-12 | 127,507 | 0 | $334,058 | $0 | +$334,058 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-16 of 16 reporting-owner rows connected to Immuneering Corp. Open a relationship link for the CIK-to-CIK filing trail.
Rows
16
Lead holder
Benjamin J. Zeskind
Net 12M change
+$721,043
Latest report
13 Mar 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Benjamin J. Zeskind | PRESIDENT AND CEO, Director | $9,928,137 | +$85,023 | +0.86% | Mixed | 03 Feb 2026 |
| Cormorant Asset Management, LP | 10%+ Owner | $8,598,961 | Filing P/S | 01 Apr 2024 | ||
| Peter Feinberg | Director | $6,947,380 | +$288,747 | +4.3% | Mixed | 12 Jan 2026 |
| Brett Matthew Hall | Chief Scientific Officer | $1,720,586 | +$45,118 | +2.7% | Filing P/S | 03 Feb 2026 |
| Thomas J. Schall | Director | $347,913 | +$225,107 | +183% | Filing P/S | 15 Jan 2026 |
| Mallory Morales | SVP Finance, CAO | $175,935 | +$1,917 | +1.1% | Filing P/S | 03 Feb 2026 |
| Leah R. Neufeld | Chief People Officer | $145,918 | +$18,508 | +15% | Mixed | 13 Mar 2026 |
| Harold E. Brakewood | Chief Business Officer | $52,598 | +$29,794 | +131% | Filing P/S | 03 Feb 2026 |
| Michael D. Bookman | Chief Legal Officer, Secretary | $33,261 | +$6,966 | +26% | Filing P/S | 03 Feb 2026 |
| Biren Amin | Cfo, Treasurer | $23,773 | Mixed | 12 May 2022 | ||
| Diana F. Hausman | Director | $19,862 | +$19,863 | +100% | Filing P/S | 02 Jul 2025 |
| Laurie B. Keating | Director | Mixed | 01 Jan 2026 | |||
| CARPENTER ROBERT J | Director | Mixed | 13 Jun 2025 | |||
| Igor Matushansky | Chief Medical Officer | Mixed | 03 Feb 2026 | |||
| Ann E. Berman | Director | Mixed | 13 Jun 2025 | |||
| Scott Barrett | Chief Medical Officer | Mixed | 15 Feb 2023 |
Recent insider transactions for Immuneering Corp
Showing up to 300 most recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | Reported value | Reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Leah R. Neufeld | IMRX | Class A Common Stock | Award | 14% | 3,628 | 29,598 | 13 Mar 2026 | Direct | ||
| Michael D. Bookman | IMRX | Stock Option | Award | 176,000 | 176,000 | 03 Feb 2026 | Direct | |||
| Harold E. Brakewood | IMRX | Stock Option | Award | 140,000 | 140,000 | 03 Feb 2026 | Direct | |||
| Brett Matthew Hall | IMRX | Stock Option | Award | 344,000 | 344,000 | 03 Feb 2026 | Direct | |||
| Mallory Morales | IMRX | Stock Option | Award | 140,000 | 140,000 | 03 Feb 2026 | Direct | |||
| Leah R. Neufeld | IMRX | Stock Option | Award | 140,000 | 140,000 | 03 Feb 2026 | Direct | |||
| Benjamin J. Zeskind | IMRX | Stock Option | Award | 688,000 | 688,000 | 03 Feb 2026 | Direct | |||
| Igor Matushansky | IMRX | Stock Option | Award | 140,000 | 140,000 | 03 Feb 2026 | Direct | |||
| Harold E. Brakewood | IMRX | Class A Common Stock | Purchase | 90.5% | $24,990 | $4.76 | 5,250 | 11,050 | 16 Jan 2026 | Direct |
| Thomas J. Schall | IMRX | Class A Common Stock | Purchase | 40.9% | $101,041 | $4.67 | 21,645 | 74,530 | 15 Jan 2026 | Direct |
| Brett Matthew Hall | IMRX | Class A Common Stock | Purchase | 0.61% | $10,502 | $4.57 | 2,298 | 376,496 | 15 Jan 2026 | Direct |
| Leah R. Neufeld | IMRX | Class A Common Stock | Purchase | 11.2% | $10,906 | $4.15 | 2,626 | 25,970 | 13 Jan 2026 | Direct |
| Peter Feinberg | IMRX | Class A Common Stock | Purchase | 17.3% | $86,904 | $4.35 | 20,000 | 135,441 | 12 Jan 2026 | General Partner of S4K Investments LLC. |
| Laurie B. Keating | IMRX | Stock Option | Award | 7,888 | 7,888 | 01 Jan 2026 | Direct | |||
| Peter Feinberg | IMRX | Stock Option | Award | 7,888 | 7,888 | 01 Jan 2026 | Direct | |||
| Peter Feinberg | IMRX | Class A Common Stock | Purchase | 5.02% | $50,025 | $6.67 | 7,500 | 156,766 | 03 Oct 2025 | Direct |
| Mallory Morales | IMRX | Class A Common Stock | Purchase | 1.1% | $1,917 | $6.39 | 300 | 27,533 | 01 Oct 2025 | Direct |
| Leah R. Neufeld | IMRX | Class A Common Stock | Purchase | 3.55% | $5,103 | $6.38 | 800 | 23,344 | 01 Oct 2025 | Direct |
| Michael D. Bookman | IMRX | Class A Common Stock | Purchase | 26.5% | $6,966 | $6.83 | 1,020 | 4,870 | 01 Oct 2025 | Direct |
| Peter Feinberg | IMRX | Class A Common Stock | Purchase | 5.29% | $52,730 | $7.03 | 7,500 | 149,266 | 30 Sep 2025 | Direct |
| Peter Feinberg | IMRX | Class A Common Stock | Purchase | 3.66% | $35,900 | $7.18 | 5,000 | 141,766 | 29 Sep 2025 | Direct |
| Leah R. Neufeld | IMRX | Class A Common Stock | Award | 110.1% | 11,815 | 22,544 | 15 Sep 2025 | Direct | ||
| Mallory Morales | IMRX | Class A Common Stock | Award | 113.8% | 14,497 | 27,233 | 15 Sep 2025 | Direct | ||
| Brett Matthew Hall | IMRX | Class A Common Stock | Award | 4.14% | 14,880 | 374,198 | 15 Sep 2025 | Direct | ||
| Diana F. Hausman | IMRX | Class A Common Stock | Purchase | $10,874 | $3.62 | 3,000 | 3,000 | 02 Jul 2025 | By spouse | |
| Diana F. Hausman | IMRX | Class A Common Stock | Purchase | $8,989 | $3.60 | 2,500 | 2,500 | 02 Jul 2025 | Direct | |
| Leah R. Neufeld | IMRX | Class A Common Stock | Purchase | 6.98% | $2,499 | $3.57 | 700 | 10,729 | 02 Jul 2025 | Direct |
| Benjamin J. Zeskind | IMRX | Class A Common Stock | Purchase | 0.3% | $24,792 | $3.53 | 7,015 | 2,312,852 | 02 Jul 2025 | Direct |
| Benjamin J. Zeskind | IMRX | Class A Common Stock | Purchase | 0.13% | $10,087 | $3.38 | 2,985 | 2,305,837 | 01 Jul 2025 | Direct |
| Thomas J. Schall | IMRX | Class A Common Stock | Purchase | 21.9% | $34,788 | $3.66 | 9,500 | 52,885 | 27 Jun 2025 | Direct |
| Brett Matthew Hall | IMRX | Class A Common Stock | Purchase | 1.7% | $14,596 | $2.43 | 6,007 | 359,318 | 23 Jun 2025 | Direct |
| Brett Matthew Hall | IMRX | Class A Common Stock | Purchase | 2.14% | $20,020 | $2.70 | 7,415 | 353,311 | 20 Jun 2025 | Direct |
| Harold E. Brakewood | IMRX | Class A Common Stock | Purchase | 48.7% | $4,804 | $2.53 | 1,900 | 5,800 | 20 Jun 2025 | Direct |
| Peter Feinberg | IMRX | Class A Common Stock | Purchase | 22.4% | $63,188 | $2.53 | 25,000 | 136,766 | 18 Jun 2025 | Direct |
| Benjamin J. Zeskind | IMRX | Class A Common Stock | Purchase | 0.92% | $50,144 | $2.39 | 21,000 | 2,302,852 | 18 Jun 2025 | Direct |
| Thomas J. Schall | IMRX | Class A Common Stock | Purchase | 1396% | $89,278 | $2.21 | 40,485 | 43,385 | 17 Jun 2025 | Direct |
| Diana F. Hausman | IMRX | Stock Option | Award | 33,350 | 33,350 | 13 Jun 2025 | Direct | |||
| Thomas J. Schall | IMRX | Stock Option | Award | 33,350 | 33,350 | 13 Jun 2025 | Direct | |||
| Laurie B. Keating | IMRX | Stock Option | Award | 33,350 | 33,350 | 13 Jun 2025 | Direct | |||
| Peter Feinberg | IMRX | Stock Option | Award | 33,350 | 33,350 | 13 Jun 2025 | Direct | |||
| Carpenter Robert J | IMRX | Stock Option | Award | 33,350 | 33,350 | 13 Jun 2025 | Direct | |||
| Ann E. Berman | IMRX | Stock Option | Award | 33,350 | 33,350 | 13 Jun 2025 | Direct |
* indicates a reported price that failed the local validity check.