Comparable stake leader
WELLINGTON MANAGEMENT GROUP LLP
SEC ownership of Celldex Therapeutics, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0000744218.
Disclosed value leader
WELLINGTON MANAGEMENT GROUP LLP
Comparable rows
50/50
Latest evidence
31 Mar 2026
- Public ticker
- CLDX on Nasdaq
- Parsed ownership sources
- 13F, 13D/G, and 3/4/5
- Largest SEC-reported holder
- WELLINGTON MANAGEMENT GROUP LLP
- Latest 13D/G holder
- WELLINGTON MANAGEMENT GROUP LLP
- Latest parsed ownership date
- 31 Mar 2026
- Issuer CIK
- 0000744218
- Issuer location
- Hampton, NJ
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Celldex Therapeutics, Inc. (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.
Comparable stake leader
WELLINGTON MANAGEMENT GRO...
Disclosed value leader
WELLINGTON MANAGEMENT GRO...
Comparable rows
50/50
Latest evidence
31 Mar 2026
13F
13D/G
3/4/5
Lead comparable stake: 12%
13D/G row: WELLINGTON MANAGEMENT GROUP LLP
Showing 1-8 of 50 holder rows.
Quick read
WELLINGTON MANAGEMENT GROUP LLP leads the comparable SEC ownership view at 12%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens WELLINGTON MANAGEMENT GROUP LLP's linked filing trail.
Comparable ownership
Top 5
WELLINGTON MANAGEMENT GROUP LLP
12%
Kynam Capital Management, LP
8.8%
BlackRock, Inc.
7.3%
FMR LLC
5.6%
VANGUARD CAPITAL MANAGEMENT LLC
5.2%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| WELLINGTON MANAGEMENT GROUP LLP |
13F
13D/G
Company
|
12%
from 13D/G
|
$271,538,300
8,560,476 shares
|
— | 31 Mar 2026 |
| Kynam Capital Management, LP |
13F
13D/G
Company
|
8.8%
from 13D/G
|
$185,262,785
5,840,567 shares
|
— | 31 Mar 2026 |
| BlackRock, Inc. |
13F
13D/G
Company
|
7.3%
from 13D/G
|
$170,332,752
5,369,885 shares
|
— | 31 Mar 2026 |
| FMR LLC |
13F
13D/G
Company
|
5.6%
from 13D/G
|
$118,919,804
3,749,048 shares
|
— | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
13F
Vanguard Capital Management · Company
|
5.2%
|
$109,332,337
3,446,795 shares
|
$0 | 31 Mar 2026 |
| Commodore Capital LP |
13F
13D/G
Company
|
4.6%
from 13D/G
|
$85,536,660
2,696,616 shares
|
— | 31 Mar 2026 |
| STATE STREET CORP |
13F
13D/G
Company · STATE STREET CORPORATION
|
4.2%
from 13D/G
|
$88,948,209
2,804,168 shares
|
— | 31 Mar 2026 |
| PRICE T ROWE ASSOCIATES INC /MD/ |
13F
13D/G
Company · T. Rowe Price Associates, Inc.
|
3.6%
from 13D/G
|
$66,179,000
2,086,332 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 selling over the last 12 months. Net value: -$1,323,482.
Buys
$0
Insiders: 0
Sells
$1,323,482
Insiders: 2
Net
-$1,323,482
Shares: -54,235
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 54,235
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 0 | $0 | $0 | $0 |
| 3-6 | 0 | 0 | $0 | $0 | $0 |
| 6-9 | 0 | 53,464 | $0 | $1,304,386 | -$1,304,386 |
| 9-12 | 0 | 771 | $0 | $19,096 | -$19,096 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 20 reporting-owner rows connected to Celldex Therapeutics, Inc.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
20
Largest Forms 3/4/5 holder
Anthony S. Marucci
Net 12M change
-$1,323,483
Latest report
02 Jan 2026
Recent insider transactions for Celldex Therapeutics, Inc.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Samuel Bates Martin | CLDX | Common Stock | Options Exercise | 17.1% | 4,817 | 32,942 | 02 Jan 2026 | Direct | ||
| Samuel Bates Martin | CLDX | Incentive Stock Option (Right to Buy) | Options Exercise | -7.57% | -4,817 | 58,815 | 02 Jan 2026 | Direct | ||
| Ph.D. Ronald A. Pepin | CLDX | Common Stock | Options Exercise | 2530.5% | 19,333 | 20,097 | 15 Dec 2025 | Direct | ||
| Ph.D. Ronald A. Pepin | CLDX | Incentive Stock Option (right to buy) | Options Exercise | -100% | -19,333 | 0 | 15 Dec 2025 | Direct | ||
| Freddy A. Jimenez | CLDX | Common Stock | Sale | -11.9% | $121,210 | $29.10 | -4,166 | 30,796 | 04 Dec 2025 | Direct |
| Richard M. Wright | CLDX | Common Stock | Sale | -70.3% | $1,183,177 | $24.00 | -49,298 | 20,833 | 13 Nov 2025 | Direct |
| Richard M. Wright | CLDX | Common Stock | Options Exercise | 236.6% | 49,298 | 70,131 | 13 Nov 2025 | Direct | ||
| Richard M. Wright | CLDX | Incentive Stock Option | Options Exercise | -100% | -49,298 | 0 | 13 Nov 2025 | Direct | ||
| Teri L. Lawver | CLDX | ISO (right to buy) | Award | 100,000 | 100,000 | 10 Nov 2025 | Direct | |||
| Freddy A. Jimenez | CLDX | Common Stock | Sale | -2.16% | $19,096 | $24.77 | -771 | 34,962 | 13 Aug 2025 | Direct |
| Sarah Cavanaugh | CLDX | Incentive Stock Option (right to buy) | Award | 78,000 | 78,000 | 05 Jun 2025 | Direct | |||
| Elizabeth Crowley | CLDX | Incentive Stock Option (right to buy) | Award | 85,000 | 85,000 | 05 Jun 2025 | Direct | |||
| Margo Heath-Chiozzi | CLDX | Incentive Stock Option (right to buy) | Award | 82,000 | 82,000 | 05 Jun 2025 | Direct | |||
| Freddy A. Jimenez | CLDX | Incentive Stock Option (right to buy) | Award | 75,000 | 75,000 | 05 Jun 2025 | Direct | |||
| Samuel Bates Martin | CLDX | Incentive Stock Option (right to buy) | Award | 81,000 | 81,000 | 05 Jun 2025 | Direct | |||
| Ph.D. Ronald A. Pepin | CLDX | Incentive Stock Option (right to buy) | Award | 20,000 | 20,000 | 05 Jun 2025 | Direct | |||
| Diane C. Young | CLDX | Incentive Stock Option (right to buy) | Award | 72,000 | 72,000 | 05 Jun 2025 | Direct | |||
| Tibor Keler | CLDX | Incentive Stock Option (right to buy) | Award | 93,000 | 93,000 | 05 Jun 2025 | Direct | |||
| Anthony S. Marucci | CLDX | Incentive Stock Option (right to buy) | Award | 300,000 | 300,000 | 05 Jun 2025 | Direct | |||
| Denice Torres | CLDX | Non-Qualified Stock Option (right to buy) | Award | 33,000 | 33,000 | 05 Jun 2025 | Direct | |||
| Rita Jain | CLDX | Non-Qualified Stock Option (right to buy) | Award | 16,500 | 16,500 | 05 Jun 2025 | Direct | |||
| Garry Arthur Neil | CLDX | Non-Qualified Stock Option (right to buy) | Award | 16,500 | 16,500 | 05 Jun 2025 | Direct | |||
| Harry H. Penner Jr. | CLDX | Non-Qualified Stock Option (right to buy) | Award | 16,500 | 16,500 | 05 Jun 2025 | Direct | |||
| Herbert J. Conrad | CLDX | Non-Qualified Stock Option (right to buy) | Award | 16,500 | 16,500 | 05 Jun 2025 | Direct | |||
| James J. Marino | CLDX | Non-Qualified Stock Option (right to buy) | Award | 16,500 | 16,500 | 05 Jun 2025 | Direct | |||
| Keith L. Brownlie | CLDX | Non-Qualified Stock Option (right to buy) | Award | 16,500 | 16,500 | 05 Jun 2025 | Direct | |||
| Cheryl L. Cohen | CLDX | Non-Qualified Stock Option (right to buy) | Award | 16,500 | 16,500 | 05 Jun 2025 | Direct |
* marks a reported price that did not pass the local price check.