As of November 6, 2026, AdvanSix Inc. is a publicly traded company (NYSE: ASIX); its largest reported holder is BlackRock, with 7.1% on Schedule 13G/A of April 24, 2026, then CastleKnight Master Fund LP (6.2%). The largest insider holding is Erin N. Kane, the chief executive and a director, with 623,103 shares (2.3% of shares outstanding), per Form 4 of March 3, 2026 (Schedule 13G/A, April 24, 2026).
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Is AdvanSix Inc. a real, registered company?
- AdvanSix Inc. files with the SEC under CIK 1673985 (its SEC filings).
- Its shares are listed under the ticker ASIX on NYSE (SEC company record).
- Incorporated in Delaware; business address in Parsippany, New Jersey, as its SEC filings state.
- Court and bankruptcy records: see Before you sign or pay below.
Before you sign or pay
- Court and bankruptcy: No federal court case or bankruptcy filing found under AdvanSix Inc. in our court records and SEC 8-K records (as of 2026-11-06).
- Leadership changes: the latest reported is Patrick C. Day, Chief Financial Officer (Form 8-K filed 2026-04-13). Check you are dealing with the people now in charge.
- Ownership: 5%+ holders are reported on Schedule 13D or 13G; the latest names American Century Investments (filed 2026-08-14).
Who are AdvanSix Inc.'s owners and officers?
AdvanSix Inc.: incorporated in Delaware; business address in Parsippany, New Jersey; industry Plastic Materials, Synth Resins & Nonvulcan Elastomers (Schedule 13G, 2026-08-14).
| Report | Holder | Share |
|---|---|---|
| Schedule 13G, 2026-08-14 | American Century Investment Management, Inc. | 5.1% |
| Schedule 13G, 2026-07-14 | Dimensional Fund Advisors LP | 5.2% |
| Schedule 13G, 2026-05-14 | Castleknight Master Fund LP | 6.2% |
| Schedule 13G/A, 2026-04-24 | Blackrock, Inc. | 7.1% |
| Schedule 13G/A, 2026-03-26 | The Vanguard Group | 0% |
| Schedule 13G/A, 2026-02-11 | Victory Capital Management, Inc. | 0.51% |
| Schedule 13G/A, 2026-01-30 | The Vanguard Group | 6.35% |
| Schedule 13G/A, 2026-01-21 | Dimensional Fund Advisors LP | 4.8% |
| Schedule 13G/A, 2026-01-08 | Blackrock, Inc. | 11.9% |
| Schedule 13G/A, 2025-10-30 | Victory Capital Management, Inc. | 8.12% |
Questions about who owns AdvanSix Inc.
Who owns AdvanSix Inc.?
On this page, 4 holders' latest ownership filings report 5% or more of AdvanSix Inc.: Blackrock, Inc. (7.1%, Schedule 13G/A, filed 2026-04-24), Castleknight Master Fund LP (6.2%, Schedule 13G, filed 2026-05-14), Dimensional Fund Advisors LP (5.2%, Schedule 13G, filed 2026-07-14) and American Century Investment Management, Inc. (5.1%, Schedule 13G, filed 2026-08-14).
Who are the largest shareholders of AdvanSix Inc.?
By the share each holder's latest filing reports, the largest holders of AdvanSix Inc. on this page are Blackrock, Inc. (7.1%), Castleknight Master Fund LP (6.2%) and Dimensional Fund Advisors LP (5.2%).
When did Blackrock, Inc. buy into AdvanSix Inc.?
The filings give report dates, not purchase dates. The earliest filing from Blackrock, Inc. on this page is the Schedule 13G/A, filed 2026-01-08, reporting 11.9%; its latest, Schedule 13G/A filed 2026-04-24, reports 7.1%. That earliest filing is itself an amendment, which updates an earlier report.
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%); 10 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.
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| Filed | Person | Role | Change | Effective |
|---|---|---|---|---|
| Form 8-K, 2026-04-13 | Patrick C. Day | Chief Financial Officer | appointed | 2026-04-27 |
Which insiders own AdvanSix Inc. shares?
Directors, officers and holders of 10% or more report their shares on Forms 3, 4 and 5. Each line is the latest such report, largest holding first.
- , the chief executive and a director: 623,103 shares (2.3% of shares outstanding) (Form 4, 2026-03-03).
- , a director: 91,946 shares (0.34% of shares outstanding) (Form 4, 2026-06-24).
- , a director: 80,953 shares (0.30% of shares outstanding) (Form 4, 2026-06-24).
- , the chief financial officer and vice president: 73,025 shares (0.27% of shares outstanding) (Form 4, 2026-03-03).
- , the senior vice president and chief hr officer: 65,029 shares (0.24% of shares outstanding) (Form 4, 2026-03-03).
Shares outstanding: 27,008,608 as of 2026-10-23, from the company's latest SEC cover page.
How much has AdvanSix Inc. raised?
No fundraising or offering filing from AdvanSix Inc. is on file with us.
Keep reading
More on AdvanSix Inc. and the records around it.
AdvanSix Inc. elsewhere on the record
- 5%+ stake filings Aug 2026
- Leadership changes Apr 2026
Companies that share a holder
- CastleKnight Master Fund LP also filed stake reports on 17 other companies: Suja Life, Inc. (Aug 2026), Advantage Solutions Inc. (Aug 2026), HAIN CELESTIAL GROUP INC (Aug 2026)
- Victory Capital Management, Inc. also filed stake reports on 41 other companies: Angel Oak Mortgage REIT, Inc. (Nov 2026), Bowhead Specialty Holdings Inc. (Jul 2026), Dole plc (Jul 2026)
- American Century Investment Management, Inc. also filed stake reports on 83 other companies: Visteon Corporation (Oct 2026), MarineMax, Inc. (Sep 2026), Allegiant Travel Company (Aug 2026)
Related pages
Filings, cases and notices link to their records. A not-found line names the records searched; it is not proof of absence.
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https://mentionfox.com/who-owns/advansix