Arthur J. Gallagher & Co.
MX ˙ BMV ˙ US3635761097
SecurityMX:AJG / Arthur J. Gallagher & Co.
InstitutionMercer Global Advisors Inc /adv
Latest Disclosed Ownership47,610 shares
Latest Disclosed Value $ 10,311,310
Mercer Global Advisors Inc /adv reports 69.36% decrease in ownership of AJG / Arthur J. Gallagher & Co.

On May 15, 2026 - Mercer Global Advisors Inc /adv filed a 13F-HR form disclosing ownership of 47,610 shares of Arthur J. Gallagher & Co. (MX:AJG) valued at $10,311,310 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 155,398 shares of Arthur J. Gallagher & Co.. This represents a change in shares of -69.36% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F GALLAGHER ARTHUR J COM 363576109 47,610 -107,788 -69.36 10,311 -74.50 0.0153
2026-02-17 2025-12-31 13F GALLAGHER ARTHUR J COM 363576109 155,398 54,678 54.29 40,436 29.62 0.0616
2025-11-14 2025-09-30 13F GALLAGHER ARTHUR J COM 363576109 100,720 60,922 153.08 31,197 144.87 0.0521
2025-08-14 2025-06-30 13F GALLAGHER ARTHUR J COM 363576109 39,798 3,221 8.81 12,740 0.89 0.0259
2025-05-15 2025-03-31 13F GALLAGHER ARTHUR J COM 363576109 36,577 -599 -1.61 12,628 19.66 0.0290
2025-02-14 2024-12-31 13F GALLAGHER ARTHUR J COM 363576109 37,176 -482,161 -92.84 10,553 -92.90 0.0257
2024-11-14 2024-09-30 13F GALLAGHER ARTHUR J COM 363576109 519,337 856 0.17 148,685 10.59 0.3480
2024-08-12 2024-06-30 13F GALLAGHER ARTHUR J COM 363576109 518,481 220 0.04 134,447 104,122.48 0.3665
2024-05-15 2024-03-31 13F GALLAGHER ARTHUR J COM 363576109 518,261 782 0.15 130 11.21 0.3683
2024-02-15 2023-12-31 13F GALLAGHER ARTHUR J COM 363576109 517,479 490,438 1,813.68 116 1,833.33 0.3500
2023-11-15 2023-09-30 13F/A-1 GALLAGHER ARTHUR J & COM 363576109 27,041 -10,618 -28.20 6 -25.00 0.0234
2023-11-14 2023-09-30 13F GALLAGHER ARTHUR J & COM 363576109 27,041 -10,618 6 0.0234
2023-08-14 2023-06-30 13F GALLAGHER ARTHUR J COM 363576109 37,659 19,753 110.31 8 166.67 0.0328
2023-05-16 2023-03-31 13F GALLAGHER ARTHUR J COM 363576109 17,906 612 3.54 3 0.00 0.0156
2023-02-09 2022-12-31 13F GALLAGHER ARTHUR J COM 363576109 17,294 1,271 7.93 3 -99.89 0.0163
2022-11-15 2022-09-30 13F GALLAGHER ARTHUR J COM 363576109 16,023 1,303 8.85 2,744 14.29 0.0163
2022-08-10 2022-06-30 13F GALLAGHER ARTHUR J COM 363576109 14,720 976 7.10 2,401 0.04 0.0147
2022-05-10 2022-03-31 13F GALLAGHER ARTHUR J COM 363576109 13,744 944 7.38 2,400 10.50 0.0141
2022-02-04 2021-12-31 13F GALLAGHER ARTHUR J COM 363576109 12,800 3,323 35.06 2,172 54.15 0.0134
2021-11-10 2021-09-30 13F GALLAGHER ARTHUR J COM 363576109 9,477 2,047 27.55 1,409 35.35 0.0098
2021-08-10 2021-06-30 13F GALLAGHER ARTHUR J COM 363576109 7,430 636 9.36 1,041 22.90 0.0080
2021-08-10 2021-03-31 13F/A-1 GALLAGHER ARTHUR J COM 363576109 6,794 -207 -2.96 847 -2.19 0.0077
2021-05-11 2021-03-31 13F GALLAGHER ARTHUR J COM 363576109 6,794 -207 847 0.0081
2021-02-12 2020-12-31 13F GALLAGHER ARTHUR J COM 363576109 7,001 -286 -3.92 866 12.61 0.0108
2020-12-10 2020-09-30 13F GALLAGHER ARTHUR J COM 363576109 7,287 -1,425 -16.36 769 -9.42 0.0116
2020-08-10 2020-06-30 13F GALLAGHER ARTHUR J COM 363576109 8,712 -6,334 -42.10 849 -30.75 0.0154
2020-05-18 2020-03-31 13F GALLAGHER ARTHUR J COM 363576109 15,046 -1,654 -9.90 1,226 -22.89 0.0270
2020-02-13 2019-12-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 16,700 -1,214 -6.78 1,590 -0.87 0.0318
2019-11-12 2019-09-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 17,914 375 2.14 1,604 4.43 0.0377
2019-08-14 2019-06-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 17,539 372 2.17 1,536 14.54 0.0407
2019-04-23 2019-03-31 13F/A-1 GALLAGHER ARTHUR J & CO COM COM 363576109 17,167 17,167 1,341 0.0482
2019-04-12 2019-03-31 13F GALLAGHER ARTHUR J COM 363576109 2,729 201 0.0107
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.