Marsh & McLennan Companies, Inc.

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 1,508 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

• TICKER. Marsh & McLennan changed its NYSE ticker symbol from MMC to MRSH effective 14 Jan 2026, as part of a rebrand of the company and its operating businesses to 'Marsh'. The legal name (Marsh & McLennan Companies, Inc.) and CUSIP (571748102) were unchanged by the switch. SEC EDGAR's own company-tickers field for CIK 0000062709 now shows MRSH, matching this project's 13F register file (data/registers/MRSH.json, cusip 571748102). Source: https://www.corporate.marsh.com/news-events/2025/december/marsh-mclennan-to-change-nyse-symbol-to-mrsh.html and the businesswire release dated 29 Dec 2025.
• HOLDINGS ARE EMPTY, SOURCED. Marsh & McLennan's operating businesses (Marsh, Guy Carpenter, Mercer, Oliver Wyman) are wholly owned subsidiaries and excluded from holdings per the brief. Searched the Q2 2026 10-Q (mrsh-20260630.htm) and the FY2025 10-K (mrsh-20251231.htm) for 'equity method', 'unconsolidated', 'joint venture', 'equity investments', 'investment in', 'affiliate', 'Alexander Forbes', 'MMA', 'minority interest', 'noncontrolling'. No named, individually sized minority stake in any other public or private company was found. What the filings do disclose are two COMBINED balances, neither of which sizes an individual investee, so per the brief's caution (c) neither is recorded as a holding: (1) 'investments in certain private equity funds' of $234 million at 30 Jun 2026 ($220 million at 31 Dec 2025), an unnamed basket of funds investing primarily in financial services companies, with $210 million of further committed but unfunded capital; (2) 'investments in private insurance brokerage and consulting companies' with a combined carrying value of $82 million at 30 Jun 2026 ($81 million at 31 Dec 2025), also unnamed. A third item, the Company's 'increased investment in Carpenter Turner Cyprus Ltd.' in Q1 2025, was a step-up to full consolidation (the prior equity-method stake was remeasured to fair value and the entity became a subsidiary), so it is a past minority stake that no longer exists, not a current holding. The brief's historical caution about minority stakes in overseas brokers (e.g. Alexander Forbes) did not turn up any current position: 'Alexander Forbes' returns zero hits in both filings.
• THOUSANDS TRAP. T. Rowe Price's Q2 2026 13F-HR info table reports the MRSH position's value column as 2,239,823 against 13,438,662 shares, an implied price of $0.167/share against a ~$166.67/share implied price on every other filer's Q2 2026 line for this issuer. Rescaled by x1000 to $2,239,823,000 in the register above; see that row's method_note.
• VANGUARD CASE: successor case, not the single-parent case. Vanguard Group Inc (CIK 0000102909) filed 13F-NT (notice only, no holdings) for the quarter ended 30 Jun 2026. Per the brief's rule, its position is represented by summing the two successor entities that actually filed 13F-HR: Vanguard Capital Management LLC (CIK 0002100119) and Vanguard Portfolio Management LLC (CIK 0002100121). Smaller Vanguard-affiliated 13F filers were not individually checked and may hold additional MRSH shares not captured here.
• CAPITAL GROUP: all three named entities hold. Capital World Investors (CIK 0001422849), Capital International Investors (CIK 0001562230), and Capital Research Global Investors (CIK 0001422848) each filed a separate Q2 2026 13F-HR reporting MRSH under CUSIP 571748102; all three were checked and all three hold. Combined into one 'Capital Group' row totaling 44,825,446 shares, $7,471,084,204, which is this register's largest single position and would have been understated by roughly 60% (18,122,340 vs 44,825,446 shares) had only Capital World Investors been checked.
• Percentages use 477,211,268 common shares outstanding as of 16 July 2026 (Q2 2026 10-Q cover page) for the twelve institutional register rows, and 483,095,948 shares as of the 2026 proxy's record date for the two proxy-sourced insider rows (the proxy states insider ownership individually and as a group is under 1%, consistent with the 0.157% and 0.379% computed here).
• Market capitalisation ($88.28bn) and share price ($184.99) are stockanalysis.com's figures as of 17 August 2026. Cross-check: 477,211,268 shares x $184.99 implies approximately $88.28 billion, matching the reported market cap almost exactly.
• The 2026 proxy also reports pre-13F Schedule 13G data as of 31 Dec 2025: The Vanguard Group at 43,794,070 shares (9.0%) and BlackRock, Inc. at 40,997,160 shares (8.4%), the only two 5%+ holders it names. The register instead uses each manager's Q2 2026 13F-HR (30 Jun 2026 position dates) as instructed; Vanguard's Q2 13F successor total (44,043,087) is modestly higher than the Dec 2025 13G figure and BlackRock's Q2 13F total (39,502,046) is modestly lower, both consistent with normal quarter-to-quarter position changes rather than a data error.
• No Schedule 13D or 13G has been filed on Marsh & McLennan / Marsh common stock since 13 Feb 2024, per the EDGAR filing index for CIK 0000062709 (which fully covers 2018 to present, confirmed via the submissions API's 'recent' window and no gap in the older-filings pagination). The register therefore leans entirely on Q2 2026 13F-HR data plus the proxy's own summary of the most recent 13G/A filings, rather than a fresh independent 13G/A cross-check for 2025 or 2026.
• Self-gate check: summing the twelve non-aggregate, non-insider register rows (Vanguard, Capital Group, BlackRock, State Street, Wellington, Geode, T. Rowe Price, FMR, MFS, Morgan Stanley, Northern Trust, JPMorgan) gives 224,090,546 shares against 477,211,268 shares outstanding, or 46.96%. This is above the 25 to 45 percent 'expect' band but within the 15 to 55 percent acceptable range; it is driven by three unusually large, individually verified positions (Vanguard 9.23%, Capital Group 9.39%, BlackRock 8.28%, together 26.9% of the company), not by any double-counted holder: each row above was checked to hold under a single CUSIP (571748102) and no manager or successor entity appears in more than one row.