As of November 6, 2026, 3 holders' latest Schedule 13D or 13G filings report owning 5% or more of Definium Therapeutics Inc. The largest reported stake is Fmr LLC's, at 6.5%. 9 filings are on record since November 14, 2025 (Schedule 13G, November 5, 2026).
Sell to companies like Definium Therapeutics Inc? Enter your website and see 10 with a filed reason to buy from you this month. Free.
Opens in a new tab. No signup.
Key facts
- · Reporting person: Fmr LLC · Sole voting: 8,733,064 · Shared voting: 0 · Sole dispositive: 8,791,720 · Shared dispositive: 0 · SCHEDULE 13G, 2026-11-05
- · Reporting person: Driehaus Capital Management LLC · Sole voting: 0 · Shared voting: 6,845,276 · Sole dispositive: 0 · Shared dispositive: 6,845,276 · SCHEDULE 13G/A, 2026-08-14
- · Reporting person: Commodore Capital LP · Sole voting: 0 · Shared voting: 2,410,000 · Sole dispositive: 0 · Shared dispositive: 2,410,000 · SCHEDULE 13G/A, 2026-08-14
- · Reporting person: Deep Track Capital, LP · Sole voting: 0 · Shared voting: 3,000,000 · Sole dispositive: 0 · Shared dispositive: 3,000,000 · SCHEDULE 13G/A, 2026-05-15
- · Holder: Avoro Capital Advisors LLC · Percent: 5.08% · SCHEDULE 13G
Definium Therapeutics Inc has 9 Schedule 13D or 13G filings on record since 2025-11-14. 3 holders' latest filing reports 5% or more of common stock. Each figure below is the holder's own, as filed, with the filing linked.
Holders
| Holder | Percent | Shares | Latest | Event date |
|---|---|---|---|---|
| Fmr LLC | 6.5% | 8,791,720 | SCHEDULE 13G, 2026-11-05 | 2026-09-30 |
| Driehaus Capital Management LLC | 5.36% | 6,845,276 | SCHEDULE 13G/A, 2026-08-14 | 2026-06-30 |
| Avoro Capital Advisors LLC | 5.08% | 5,000,000 | SCHEDULE 13G, 2026-02-17 | 2025-12-31 |
| Deep Track Capital, LP | 3.01% | 3,000,000 | SCHEDULE 13G/A, 2026-05-15 | 2026-03-31 |
| Commodore Capital LP | 1.8% | 2,410,000 | SCHEDULE 13G/A, 2026-08-14 | 2026-06-30 |
Holding shares or following this stake? See who's behind Definium Therapeutics Inc and the warning signs.
Free to see. No signup.
Keep reading
More on Definium Therapeutics Inc and the records around it.
Definium Therapeutics Inc elsewhere on the record
- Form D filing May 2025
- Who owns it
Companies that share a holder
- DRIEHAUS CAPITAL MANAGEMENT LLC also filed stake reports on 16 other companies: Cardinal Infrastructure Group Inc. (Aug 2026), Cue Biopharma, Inc. (Aug 2026), Frequency Electronics, Inc. (Aug 2026)
- Avoro Capital Advisors LLC also filed stake reports on 18 other companies: Arrowhead Pharmaceuticals, Inc. (Aug 2026), Avalo Therapeutics, Inc. (Aug 2026), Hemab Therapeutics Holdings, Inc. (Aug 2026)
- Commodore Capital LP also filed stake reports on 40 other companies: Sagimet Biosciences Inc. (Oct 2026), Surrozen, Inc./DE (Oct 2026), JATT III Acquisition Corp (Sep 2026)
Watch Definium Therapeutics Inc
Get an email when Definium Therapeutics Inc files again: a new raise, a leadership change, a layoff or an IPO filing. One email first to confirm; nothing else until you click it. At most one a day, one click to stop. Free for up to 3 companies.
Want the whole picture on Definium Therapeutics Inc?
Example from a real report (our sample on Target): “Target eliminated approximately 1,800 corporate positions, with around 1,000 employees receiving layoff notices and the remainder accounted for by eliminating open roles.” Source: NBC News
A Full Report on Definium Therapeutics Inc: verified, sourced, every claim cited, ready in a few minutes. See pricing.
What the Full Report on Definium Therapeutics Inc covers
The Short Answer
Which Company This Is
What They Do, And How The Money Works
Who Runs It, And How To Reach Them
The Money: Funding, Valuation, Runway
Who Pays Them, And Who They Are Up Against
Warning Bells
Sources
10 cited sources found
Plus the sections for what you are deciding, which you pick after ordering.
A real finished report, first screen. Opens in a new tab.
Not ready to order yet? Keep this snapshot.
Sends this preview to you once; we won't add you to any list
Voting and dispositive power, as filed
| Reporting person | Sole voting | Shared voting | Sole dispositive | Shared dispositive | Filing |
|---|---|---|---|---|---|
| Fmr LLC | 8,733,064 | 0 | 8,791,720 | 0 | SCHEDULE 13G, 2026-11-05 |
| Abigail P. Johnson | 0 | 0 | 8,791,720 | 0 | SCHEDULE 13G, 2026-11-05 |
| Driehaus Capital Management LLC | 0 | 6,845,276 | 0 | 6,845,276 | SCHEDULE 13G/A, 2026-08-14 |
| Deep Track Capital, LP | 0 | 3,000,000 | 0 | 3,000,000 | SCHEDULE 13G/A, 2026-05-15 |
| Deep Track Biotechnology Master Fund, Ltd. | 0 | 3,000,000 | 0 | 3,000,000 | SCHEDULE 13G/A, 2026-05-15 |
| David Kroin | 0 | 3,000,000 | 0 | 3,000,000 | SCHEDULE 13G/A, 2026-05-15 |
| Commodore Capital LP | 0 | 2,410,000 | 0 | 2,410,000 | SCHEDULE 13G/A, 2026-08-14 |
| Commodore Capital Master LP | 0 | 2,410,000 | 0 | 2,410,000 | SCHEDULE 13G/A, 2026-08-14 |
| Robert Egen Atkinson | 0 | 2,410,000 | 0 | 2,410,000 | SCHEDULE 13G/A, 2026-08-14 |
| Michael Kramarz | 0 | 2,410,000 | 0 | 2,410,000 | SCHEDULE 13G/A, 2026-08-14 |
The latest filing identifies Definium Therapeutics Inc by CUSIP 24477V105 and gives its principal executive office as ONE WORLD TRADE CENTER, SUITE 8500, NEW YORK, NY 10007 (SCHEDULE 13G, 2026-11-05).
Timeline
| Filed | Holder | Percent | Filing |
|---|---|---|---|
| 2025-11-14 | Deep Track Capital, LP | 6.87% | SCHEDULE 13G/A |
| 2026-02-13 | Deep Track Capital, LP | 5.54% | SCHEDULE 13G/A |
| 2026-02-17 | Avoro Capital Advisors LLC | 5.08% | SCHEDULE 13G |
| 2026-02-17 | Driehaus Capital Management LLC | 6.64% | SCHEDULE 13G |
| 2026-02-17 | Commodore Capital LP | 7.2% | SCHEDULE 13G/A |
| 2026-05-15 | Deep Track Capital, LP | 3.01% | SCHEDULE 13G/A |
| 2026-08-14 | Driehaus Capital Management LLC | 5.36% | SCHEDULE 13G/A |
| 2026-08-14 | Commodore Capital LP | 1.8% | SCHEDULE 13G/A |
| 2026-11-05 | Fmr LLC | 6.5% | SCHEDULE 13G |
Questions about who owns Definium Therapeutics Inc
Who owns Definium Therapeutics Inc?
On this page, 3 holders' latest ownership filings report 5% or more of Definium Therapeutics Inc: Fmr LLC (6.5%, Schedule 13G, filed 2026-11-05), Driehaus Capital Management LLC (5.36%, Schedule 13G/A, filed 2026-08-14) and Avoro Capital Advisors LLC (5.08%, Schedule 13G, filed 2026-02-17).
Who are the largest shareholders of Definium Therapeutics Inc?
By the share each holder's latest filing reports, the largest holders of Definium Therapeutics Inc on this page are Fmr LLC (6.5%), Driehaus Capital Management LLC (5.36%) and Avoro Capital Advisors LLC (5.08%).
When did Fmr LLC buy into Definium Therapeutics Inc?
The filings give report dates, not purchase dates. The earliest filing from Fmr LLC on this page is the Schedule 13G, filed 2026-11-05, reporting 6.5%.
Is this an audit or a full list?
Neither. The ownership list on this page covers only Schedule 13D and 13G filings, which holders make once they own 5% or more of a class of shares (an amendment can report a stake that has since fallen below 5%); 9 such filings are shown here. It is not an audit and not a full cap table: holders who never reached 5% are not listed, and a stake can change after its latest filing.
Also on the record for Definium Therapeutics Inc
| Date | Record | Figure | Our page | Source |
|---|---|---|---|---|
| May 5, 2025 | Form D, private offering | $7M sold | Form D page | Source |
Tools for this story
Each opens in a new tab, filled in for Definium Therapeutics Inc. With no account yet, you sign up free and land on the result.
Where this comes from
Anyone who comes to own more than 5% of a class of a listed company's voting shares has to tell the SEC. A holder who may seek to change or influence the company files Schedule 13D, and has to say in Item 4, "Purpose of Transaction", what it intends to do. A holder with no such intent, such as many index and passive funds, may file the shorter Schedule 13G. Both are amended when the stake changes, including when it falls below 5%.
Every row here is one of those filings, linked to the filing itself. Percentages and share counts are exactly as the holder filed them, for the holder the filing names; an amendment showing a lower figure is shown as filed. Item 4 text is quoted word for word. Where a 13D's Item 4 contains a sentence stating a definite intent to influence the company, that sentence is marked and quoted; the page does not describe the holder or its motives beyond the words it filed. Nothing here is investment advice.