ABIVAX SA (ABVX) Institutional Ownership & Top Holders
The most recent SEC Form 13F filings (Q2 2026) show 13 hedge funds and institutional investors holding a combined 12.7M shares of ABIVAX SA (ABVX), valued at $1.6B. The median portfolio weight is 7.3%.
The latest institutional ownership changes for ABVX show net buying, with the combined position up by 2.1M shares (20.0%) from the previous quarter.
Among 13F filers, the funds with the highest portfolio allocation to ABVX are Kite Lake Capital Management (14.2% of its 13F portfolio), Octagon Capital Advisors (12.1%), and Helikon Investments (11.1%). In Q2 2026, Helikon Investments made the largest position increase (+6.8%), while Davern Capital Partners made the largest reduction (-2.4%).
Top 10 Institutional Holders in ABIVAX SA (ABVX), Ranked by Portfolio Weight
Based on the latest SEC Form 13F filings (Q2 2026).
| # | Fund | Shares | Market Value | Portfolio Weight |
|---|---|---|---|---|
| 1 | Kite Lake Capital Management | 300,600 | $40.1M | 14.2% |
| 2 | Octagon Capital Advisors | 993,000 | $132.3M | 12.1% |
| 3 | Helikon Investments | 2,787,131 | $371.4M | 11.1% |
| 4 | Caligan | 1,557,924 | $207.6M | 10.0% |
| 5 | Saturn V Capital Management | 518,865 | $69.1M | 9.9% |
| 6 | Darwin Global Management | 3,621,583 | $348.2M | 9.3% |
| 7 | Vestal Point Capital | 2,349,443 | $313.1M | 7.3% |
| 8 | Melqart | 307,250 | $40.9M | 3.9% |
| 9 | Exome Asset Management | 46,878 | $6.2M | 3.9% |
| 10 | SAMSARA BIOCAPITAL | 55,095 | $7.3M | 0.6% |
- 13Institutional investors
- 12,659,169Shares held (disclosed)
- $1.6B13F market value
- 7.3%Median portfolio weight
Ownership History
Quarter-by-quarter share count, market value, and portfolio conviction weight (up to 5 of the heaviest weight-by-portfolio funds) of ABVX. Sourced from 13F filings; reflects long equity positions only.
Quarter-over-Quarter ActivityQ2 2026
The biggest weight-increase and weight-decrease changes among funds that hold ABVX. Deltas compare the selected filing to the previous reporting quarter.
Top buyers
- Helikon Investments+6.8% · +1,773,807 shares
- Melqart+3.9% · +307,250 shares
- Exome Asset Management+3.9% · +46,878 shares
Top sellers
- Davern Capital Partners-2.4% · -78,125 shares
- Paradigm Biocapital Advisors-1.8% · -772,473 shares
- Saturn V Capital Management-1.0% · -23,831 shares
Options Activity
- Total calls29,700 (+0)
Ownership Statistics
- Funds holding
- 13
- Median weight
- 7.3%
- Largest holder
- Kite Lake Capital Management · 14.2%
- Smallest holder
- RTW Investments · 0.0%
- Shares held
- 12,659,169 (+2,112,593)
All Institutional HoldersSortable · searchable
All institutional investors (Max 50) holding ABVX in the selected quarter. Click a fund name to drill into its full 13F portfolio.
| 1 | Kite Lake Capital Management | 300,600 | $40.1M | 14.2% |
| 2 | Octagon Capital Advisors | 993,000 | $132.3M | 12.1% |
| 3 | Helikon Investments | 2,787,131 | $371.4M | 11.1% |
| 4 | Caligan | 1,557,924 | $207.6M | 10.0% |
| 5 | Saturn V Capital Management | 518,865 | $69.1M | 9.9% |
| 6 | Darwin Global Management | 3,621,583 | $348.2M | 9.3% |
| 7 | Vestal Point Capital | 2,349,443 | $313.1M | 7.3% |
| 8 | Melqart | 307,250 | $40.9M | 3.9% |
| 9 | Exome Asset Management | 46,878 | $6.2M | 3.9% |
| 10 | SAMSARA BIOCAPITAL | 55,095 | $7.3M | 0.6% |
| 11 | Senator | 55,000 | $7.3M | 0.3% |
| 12 | Maverick Capital | 40,000 | $5.3M | 0.0% |
| 13 | RTW Investments | 26,400 | $3.5M | 0.0% |
Institutional Investor Count Over Time
Number of institutional investors disclosing a long position in ABIVAX SA (ABVX) each reporting quarter. Sourced from SEC Form 13F-HR filings.
Methodology & FAQ
Methodology: How We Track ABVX Institutional Holdings
Our data is systematically aggregated directly from quarterly Form 13F-HR disclosures submitted to the U.S. Securities and Exchange Commission (SEC).
- Who must file: This dataset includes filings from U.S. institutional investment managers, hedge funds, mutual funds, university endowments, and family offices managing at least $100 million in Section 13(f) securities (including equities, options, convertibles, ETFs, and warrants).
- What is included: We capture long positions in Section 13(f) securities for ABIVAX SA (ABVX). By SEC regulation, 13F filings do not require the disclosure of short positions, non-U.S. holdings, or OTC derivatives. Listed options are excluded from portfolio weight calculations to ensure comparability across filers.
- Metric definition: “Portfolio Weight” shows how much of a fund's total reported 13F portfolio value (excluding listed options) is allocated to ABVX on the specific reporting date.
- How to use this data: Quarter-over-quarter changes in shares and portfolio weight reflect a combination of active trading and market price movements. These are descriptive metrics of fund allocation, not explicit buy or sell signals.
How do you measure hedge fund conviction and institutional concentration in ABVX?
We evaluate fund conviction by looking at portfolio weight rather than just absolute share count. By tracking how the largest holders , such as Kite Lake Capital Management , Octagon Capital Advisors , and Helikon Investments as of Q2 2026, change their position sizing quarter-over-quarter, we help investors distinguish between deliberate position sizing changes and passive mark-to-market drift.
Does the ABVX ownership data include short interest or options?
SEC Form 13F mandates the disclosure of long positions in Section 13(f) securities, which includes equities and listed options (put and call contracts), but excludes short interest, swaps, and OTC derivatives by regulatory design. On this platform, listed options are excluded from portfolio weight calculations to ensure comparability across filers.
Are family offices and university endowments included in this ABVX data?
Yes. In addition to traditional hedge funds and large asset managers, any institutional entity exercising investment discretion over at least $100 million in Section 13(f) securities must file a Form 13F. This explicitly includes single-family offices and university endowments. If a qualifying family office or endowment holds ABVX stock, their allocation is systematically aggregated alongside traditional fund data.
When is the institutional ownership data updated, and is there a reporting lag?
Institutional investment managers are required to file their Form 13F within 45 days after the end of a calendar quarter (the standard “T+45” window). Our platform re-ingests new filings from the SEC EDGAR database on a nightly cycle, typically within 24–48 hours of publication, providing a point-in-time snapshot of reported consensus positioning for ABVX as of each filing date.