Rock Springs Capital CLDX Position
Active10-Fund ConvergenceRock Springs Capital trimmed their position in Celldex Therapeutics Inc. (CLDX) in Q4 2025, holding $18.8M worth of shares across 692,538 shares.
The position was first reported in Q1 2023 and has been tracked across 12 quarterly 13F filings.
CLDX is a convergence signal: 10 specialist biotech funds hold this stock, suggesting high institutional conviction.
There is an upcoming Phase 2 readout for barzolvolimab in 75 days (Jun 30, 2026), making the timing of Rock Springs's position particularly relevant.
Short interest stands at 16.4% of float with 9.4 days to cover, indicating significant bearish positioning against Rock Springs's long thesis.
About Celldex Therapeutics Inc.
Celldex Therapeutics, Inc., a biopharmaceutical company, engages in developing therapeutic monoclonal and bispecific antibodies for the treatment of various diseases. Its drug candidates include antibody-based therapeutics to treat patients with inflammatory diseases and various forms of cancer. The company's clinical development programs CDX-0159, a Phase I monoclonal antibody that binds the receptor tyrosine kinase KIT and inhibits its activity; CDX-1140, a human agonist monoclonal antibody targeted to CD40, a key activator of immune response, which is found on dendritic cells, macrophages, and B cells, as well as is expressed on various cancer cells; and CDX-527, a bispecific antibody, which uses the company's proprietary active anti-PD-L1 and CD27 human antibodies to couple CD27 costimulation with blockade of the PD-L1/PD-1 pathway to help prime and activate anti-tumor T cell responses through CD27 costimulation. The company has research collaboration and license agreements with University of Southampton to develop human antibodies towards CD27; Amgen Inc. with exclusive rights to CDX-301 and CD40 ligand; and Yale University. Celldex Therapeutics, Inc. was incorporated in 1983 and is headquartered in Hampton, New Jersey.
Full company profile →Short Interest
16.4%
9.4 days to cover
Rock Springs Capital CLDX Position History
| Quarter | Action | Shares | Change | Value |
|---|---|---|---|---|
| Q4 2025 | Decreased | 692,538 | -29,000 | $18.8M |
| Q3 2025 | Decreased | 721,538 | -91,115 | $18.7M |
| Q2 2025 | Held | 812,653 | — | $16.5M |
| Q1 2025 | Decreased | 812,653 | -409,529 | $14.8M |
| Q4 2024 | Increased | 1,222,182 | +118,404 | $30.9M |
| Q3 2024 | Decreased | 1,103,778 | -295,216 | $37.5M |
| Q2 2024 | Increased | 1,398,994 | +26,809 | $51.8M |
| Q1 2024 | Increased | 1,372,185 | +402,539 | $57.6M |
| Q4 2023 | Increased | 969,646 | +469,545 | $38.5M |
| Q3 2023 | Increased | 500,101 | +78,486 | $13.8M |
| Q2 2023 | Increased | 421,615 | +111 | $14.3M |
| Q1 2023 | New | 421,504 | +421,504 | $15.2M |
Frequently Asked Questions
Does Rock Springs Capital own CLDX?
Yes. As of Q4 2025, Rock Springs Capital holds 692,538 shares of Celldex Therapeutics Inc. (CLDX) valued at $18.8M. This data comes from their SEC 13F filing.
How many hedge funds own CLDX?
10 specialist biotech hedge funds currently hold CLDX, including Eventide Asset Management, RTW Investments, Commodore Capital and 6 more. When 3 or more specialist funds hold the same stock, BiotechEdge flags it as a convergence signal.
When did Rock Springs Capital first buy CLDX?
Rock Springs Capital's position in CLDX was first reported in Q1 2023. 13F filings are reported with a 45-day delay, so the actual purchase may have occurred earlier in the quarter.
Is Rock Springs Capital's CLDX position increasing or decreasing?
Rock Springs Capital trimmed their CLDX position in the most recent quarter, reducing by 29,000 shares.
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