GW PHARMACEUTICALS PLC (GWPH) Institutional Ownership & Top Holders
The most recent SEC Form 13F filings (Q1 2021) show 3 hedge funds and institutional investors holding a combined 3.3M shares of GW PHARMACEUTICALS PLC (GWPH), valued at $719.0M. The median portfolio weight is 4.3%.
Institutional ownership changes in GWPH reflect net buying, as the combined position increased by 3.2M shares (2065.7%) from the previous quarter.
Among 13F filers, the funds with the highest portfolio allocation to GWPH are Pentwater Capital Management (5.3% of its 13F portfolio), Melqart (4.3%), and Glazer Capital (3.1%). In Q1 2021, Pentwater Capital Management made the largest position increase (+5.3%), while Tri Locum Partners made the largest reduction (-1.7%).
Top 3 Institutional Holders in GW PHARMACEUTICALS PLC (GWPH), Ranked by Portfolio Weight
Based on the latest SEC Form 13F filings (Q1 2021).
| # | Fund | Shares | Market Value | Portfolio Weight |
|---|---|---|---|---|
| 1 | Pentwater Capital Management | 2,102,104 | $455.9M | 5.3% |
| 2 | Melqart | 234,650 | $50.9M | 4.3% |
| 3 | Glazer Capital | 978,045 | $212.1M | 3.1% |
- 3Institutional investors
- 3,314,799Shares held (disclosed)
- $719.0M13F market value
- 4.3%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 GWPH. Sourced from 13F filings; reflects long equity positions only.
Quarter-over-Quarter ActivityQ1 2021
The biggest weight-increase and weight-decrease changes among funds that hold GWPH. Deltas compare the selected filing to the previous reporting quarter.
Top buyers
- Pentwater Capital Management+5.3% · +2,102,104 shares
- Melqart+4.3% · +234,650 shares
- Glazer Capital+3.1% · +978,045 shares
Top sellers
- Tri Locum Partners-1.7% · -40,159 shares
- Baker Bros. Advisors-0.0% · -112,897 shares
Ownership Statistics
- Funds holding
- 3
- Median weight
- 4.3%
- Largest holder
- Pentwater Capital Management · 5.3%
- Smallest holder
- Glazer Capital · 3.1%
- Shares held
- 3,314,799 (+3,161,743)
All Institutional HoldersSortable · searchable
All institutional investors (Max 50) holding GWPH in the selected quarter. Click a fund name to drill into its full 13F portfolio.
| 1 | Pentwater Capital Management | 2,102,104 | $455.9M | 5.3% |
| 2 | Melqart | 234,650 | $50.9M | 4.3% |
| 3 | Glazer Capital | 978,045 | $212.1M | 3.1% |
Institutional Investor Count Over Time
Number of institutional investors disclosing a long position in GW PHARMACEUTICALS PLC (GWPH) each reporting quarter. Sourced from SEC Form 13F-HR filings.
Methodology & FAQ
Methodology: How We Track GWPH 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 (Reporting Threshold): 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 (Data Scope): We capture long positions in Section 13(f) securities for GW PHARMACEUTICALS PLC (GWPH). 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.
- Portfolio Weight Explained (Metric Definition): “Portfolio Weight” shows how much of a fund's total reported 13F portfolio value (excluding listed options) is allocated to GWPH on the specific reporting date.
- How to Use This Data (Interpretation): 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 GWPH?
We evaluate fund conviction by looking at portfolio weight rather than just absolute share count. By tracking how the largest holders —such as Pentwater Capital Management , Melqart , and Glazer Capital as of Q1 2021— change their position sizing quarter-over-quarter, we help investors distinguish between deliberate position sizing changes and passive mark-to-market drift.
Does the GWPH 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 GWPH 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 GWPH 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 GWPH as of each filing date.