Smurfit Westrock plc

The full register, from 13F filings

The Register tab above is hand research: a dozen holders, each traced to the filing it came from. This asks the same question of the whole market for the quarter ended 31-mar-2026, where 598 managers reported a position. Broad where the research is deep, and shallow in the ways a 13F always is.

Built from 13F filings, which report US listed, long, US custodied positions only. A register from this source is a floor rather than a level: a holder's true position can be far larger, as BlackRock's ASML stake shows at 1.28m shares in a 13F against 26.3m in its 13G/A. Holdings held through derivatives, outside US custody, or below a manager's reporting obligation do not appear. Where a holder is marked as a family, its total sums several separate filing entities and describes something no single filing describes; the constituent entities and their share counts are listed so the total can be checked. That roll-up can legitimately exceed the family's own Schedule 13G, because a 13G is filed by one legal entity: Vanguard reports Alphabet through ten advisory entities, and The Vanguard Group Inc itself reported zero after its January 2026 disaggregation.

What a reader needs to know to read these numbers

• Smurfit Westrock plc was formed 5 July 2024 by the combination of Smurfit Kappa Group plc and WestRock Company (the 'Combination'), and is incorporated in Ireland. CIK 0002005951 is the new combined registrant and is the ONLY CIK used anywhere in this file. No figures from the legacy WestRock Company CIK or the legacy Smurfit Kappa Group plc entity are used: those are different companies with different share counts and their pre-Combination filings are not cited here.
• The company is dual listed: primary listing on the NYSE (ticker SW, used throughout this file) with a secondary standard listing on the London Stock Exchange. All figures in this file (shares outstanding, market cap, 13F holdings) are the combined worldwide totals from the registrant's own SEC filings and 13F filers' information tables, which report against the single CUSIP G8267P108 covering the one class of ordinary shares regardless of which exchange a holder trades on.
• shares_outstanding (524,522,908) is taken from the Q2 2026 10-Q cover page: 'As of July 24, 2026, the registrant had 524,522,908 ordinary shares, nominal value $0.001 per share, issued and outstanding.' This 10-Q (filed 31 Jul 2026, period 30 Jun 2026) is the newest SEC filing on record, newer than the FY2025 10-K (filed 27 Feb 2026, period 31 Dec 2025, which showed 522,310,486 shares outstanding at 31 Dec 2025 and 524,522,908 at 30 Jun 2026 on its balance sheet, matching the 10-Q cover page).
• Holdings side: searched the FY2025 10-K (period 31 Dec 2025, filed 27 Feb 2026, the newest annual filing) and the Q2 2026 10-Q (period 30 Jun 2026, filed 31 Jul 2026, the newest filing on record) in full for 'equity method', 'equity investments', 'non-marketable', 'joint venture', 'unconsolidated', 'investments in associates', 'affiliate', 'minority interest', 'equity in earnings', 'proportion', 'investment in', 'Basis of Presentation and Principles of Consolidation'. No equity-method investment, joint venture, minority stake, or non-marketable equity security was found in either filing. The only 'variable interest entities' disclosed (Note 22 in the 10-K) are the Company's OWN consolidated accounts-receivable securitization vehicles, which are consolidated subsidiaries of Smurfit Westrock, not minority stakes the Company holds in a third party, and are therefore excluded per the brief. Exhibit 21 (Significant Subsidiaries of Smurfit Westrock plc, filed with the FY2025 10-K) was checked directly and is a bare two-column list of legal-entity name and country of incorporation with NO ownership-percentage column of any kind: a genuine negative rather than evidence of looking in the wrong place. Exhibit 21 is dominated, as expected for a company formed by a large merger, by wholly owned operating subsidiaries carried over from both the Smurfit Kappa and WestRock legacy corporate structures (hundreds of entities across dozens of countries); none of these is a minority stake and none is included here. One unrelated minority-interest disclosure was noted in the 2026 proxy (not the 10-K/10-Q): the father of CEO Anthony Smurfit holds an 18% beneficial interest in Power Paperboard Limited, a supplier at the Whakatane Mill; this is a personal holding of a related person disclosed for related-party-transaction purposes and is not an investment held by Smurfit Westrock plc itself, so it is not recorded as a holdings-side row.
• Register self-gate, computed on this final file the way the chart computes it (container reduced to its residual, all member and non-member rows at full value): 12 rows, total 283,418,286 shares, 283,418,286 / 524,522,908 = 54.03% of the company. This is above the brief's expected 25-45% band and close to, but under, the 55% threshold that would mandate a documented investigation; that investigation was still done given how close the number sits to the boundary. Two corroborating checks: (1) this project's own data/registers/SW.json snapshot (31 Mar 2026, 598 distinct 13F filers) reports total_shares_reported of 476,089,273, which is 90.78% of the 524,522,908 shares outstanding used here, meaning the great majority of the company's float is already visible in aggregate to 13F filers as a class, so a concentrated top-10-plus-insiders register capturing 54% of the company from just 10 institutional families plus insiders is consistent with, not contradictory to, that near-total 13F coverage. (2) Back-solving the denominator from two of the DEF 14A's own 5%-holder rows: Vanguard's stale-13G proxy figure of 61,472,045 shares at 11.73% implies a denominator of 524,101,833; BlackRock's stale-13G proxy figure of 41,566,832 shares at 7.93% implies a denominator of 524,044,020. Both land within about 0.1% of the 524,522,908 shares_outstanding used throughout this file (the small residual gap is explained by the proxy percentages being rounded to two decimal places and dated several months earlier than the 10-Q cover page), independently confirming the denominator. Each of the 12 register rows also corresponds to a distinct filer family independently reported in the project's own SW.json snapshot at broadly the same size (Vanguard, Capital Group, BlackRock, State Street, Nuveen, Causeway, Geode, Franklin Resources, Invesco, Orbis Allan Gray all appear there), so no row here is a snapshot artefact or a double-counted holder.
• Implied-price check run on every institutional row: all eight Vanguard entities, all five Capital Group entities with holdings, BlackRock, State Street, Nuveen, Causeway, Franklin Resources, Invesco and Orbis Allan Gray each imply a per-share price between $46.25 and $46.27 (value_usd / shares), consistent with SW's actual trading range around 30 June 2026 (the 52-week range on file runs $32.73 to $52.65). Geode implies $46.08, a small ~0.4% outlier within normal same-day filing-timing noise and not treated as a units error. No row in this file shows a roughly 1000x-low implied price, so none of the known VALUES-IN-THOUSANDS filer quirks (T. Rowe Price, Cohen & Steers, SG Americas Securities) or the APG Asset Management N.V. ~12%-low quirk are triggered here; none of those specific filers appears among this file's rows.
• Given hazard 2 (dual NYSE/London listing, non-US holders that file no 13F at all), the register above is best read as a floor on institutional US-visible ownership rather than a complete picture: London-listed shares held through Euroclear/CREST by UK and European institutions that are not SEC 13F filers are structurally invisible to this methodology. That said, the 90.78% 13F-snapshot coverage figure in the note above suggests the free float is, in practice, heavily represented in the 13F universe (consistent with SW being a US-domestic SEC filer primarily traded on the NYSE, with the London listing serving a much smaller secondary pool), so the 'floor' caveat is noted but the register is not obviously understated to an unreasonable degree.
• The register was capped at 10 institutional rows plus the CEO and the officers/directors aggregate (12 rows total) once the self-gate arithmetic reached 54%, in preference to adding further named holders from the SW.json snapshot (e.g. DZ Bank AG, Deutsche Bank AG, Fidelity/FMR, Bank of New York Mellon Corp, Ameriprise Financial, Nordea, Goldman Sachs, Morgan Stanley, Bank of America, AQR Capital, Dimensional Fund Advisors, Northern Trust, Legal & General, JPMorgan, UBS, Amundi, Canada Pension Plan Investment Board, Charles Schwab Investment Management, Ruffer LLP, Soros Fund Management, all present in the snapshot below Orbis Allan Gray in size) which were not independently re-fetched from their own Q2 2026 13F-HRs here. T. Rowe Price (CIK 0000080255 Associates and CIK 0001897612 Investment Management) does not appear at all in the top 30 of the project's own SW.json snapshot and was not separately checked given the time budget; its absence from the top-30 snapshot suggests it is not a material holder of Smurfit Westrock, but this is not independently confirmed here.