Arthur J. Gallagher & Co.
MX ˙ BMV ˙ US3635761097
SecurityMX:AJG / Arthur J. Gallagher & Co.
InstitutionGilbert & Cook, Inc.
Latest Disclosed Ownership5,006 shares
Latest Disclosed Value $ 1,084,199
Gilbert & Cook, Inc. reports 6.62% increase in ownership of AJG / Arthur J. Gallagher & Co.

On May 5, 2026 - Gilbert & Cook, Inc. filed a 13F-HR form disclosing ownership of 5,006 shares of Arthur J. Gallagher & Co. (MX:AJG) valued at $1,084,199 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 7, 2026 disclosing 4,695 shares of Arthur J. Gallagher & Co.. This represents a change in shares of 6.62% 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)
2026-05-05 2026-03-31 13F GALLAGHER ARTHUR J COM 363576109 5,006 311 6.62 1,084 -10.78 0.1400
2026-01-07 2025-12-31 13F GALLAGHER ARTHUR J COM 363576109 4,695 102 2.22 1,215 -14.56 0.1527
2025-11-12 2025-09-30 13F GALLAGHER ARTHUR J COM 363576109 4,593 472 11.45 1,423 7.81 0.1828
2025-08-05 2025-06-30 13F GALLAGHER ARTHUR J COM 363576109 4,121 55 1.35 1,319 -5.99 0.1783
2025-05-06 2025-03-31 13F GALLAGHER ARTHUR J COM 363576109 4,066 -1,904 -31.89 1,404 -17.18 0.2036
2025-01-23 2024-12-31 13F GALLAGHER ARTHUR J COM 363576109 5,970 614 11.46 1,695 12.41 0.2389
2024-11-07 2024-09-30 13F GALLAGHER ARTHUR J COM 363576109 5,356 446 9.08 1,507 18.38 0.2072
2024-08-01 2024-06-30 13F GALLAGHER ARTHUR J COM 363576109 4,910 -451 -8.41 1,273 -5.00 0.1861
2024-05-02 2024-03-31 13F GALLAGHER ARTHUR J COM 363576109 5,361 -37 -0.69 1,340 10.47 0.1827
2024-02-13 2023-12-31 13F/A-1 GALLAGHER ARTHUR J COM 363576109 5,398 259 5.04 1,214 3.59 0.1718
2024-02-05 2023-12-31 13F GALLAGHER ARTHUR J COM 363576109 5,398 259 1,214 0.1718
2023-11-02 2023-09-30 13F GALLAGHER ARTHUR J COM 363576109 5,139 427 9.06 1,171 13.25 0.1847
2023-08-14 2023-06-30 13F GALLAGHER ARTHUR J COM 363576109 4,712 309 7.02 1,035 22.80 0.1659
2023-05-05 2023-03-31 13F GALLAGHER ARTHUR J COM 363576109 4,403 55 1.26 842 2.81 0.1454
2023-02-09 2022-12-31 13F GALLAGHER ARTHUR J COM 363576109 4,348 73 1.71 820 3.41 0.1492
2022-11-03 2022-09-30 13F GALLAGHER ARTHUR J COM 363576109 4,275 70 1.66 792 15.45 0.1761
2022-08-05 2022-06-30 13F ARTHUR J GALLAGHER&C COM 363576109 4,205 171 4.24 686 -2.56 0.1233
2022-05-02 2022-03-31 13F GALLAGHER ARTHUR J COM 363576109 4,034 144 3.70 704 6.67 0.1139
2022-01-19 2021-12-31 13F GALLAGHER ARTHUR J COM 363576109 3,890 143 3.82 660 18.49 0.1062
2022-01-20 2021-09-30 13F/A-1 GALLAGHER ARTHUR J COM 363576109 3,747 163 4.55 557 10.96 0.0997
2021-10-13 2021-09-30 13F GALLAGHER ARTHUR J COM 363576109 3,687 103 557 0.0997
2021-07-13 2021-06-30 13F GALLAGHER ARTHUR J COM 363576109 3,584 144 4.19 502 17.02 0.0904
2021-04-14 2021-03-31 13F GALLAGHER ARTHUR J COM 363576109 3,440 350 11.33 429 11.72 0.0844
2021-02-11 2020-12-31 13F GALLAGHER ARTHUR J COM 363576109 3,090 512 19.86 384 41.18 0.0828
2020-11-13 2020-09-30 13F GALLAGHER ARTHUR J COM 363576109 2,578 220 9.33 272 18.26 0.0645
2020-08-05 2020-06-30 13F GALLAGHER ARTHUR J COM 363576109 2,358 2,358 230 0.0576
2020-05-05 2020-03-31 13F GALLAGHER ARTHUR J COM 363576109 0 -2,736 -100.00 0 -100.00
2020-02-03 2019-12-31 13F GALLAGHER ARTHUR J COM 363576109 2,736 336 14.00 261 21.40 0.0640
2019-11-05 2019-09-30 13F GALLAGHER ARTHUR J COM 363576109 2,400 2,400 215 0.0602
2017-10-31 2017-09-30 13F GALLAGHER ARTHUR J COM 363576109 0 -3,915 -100.00 0 -100.00
2017-07-20 2017-06-30 13F GALLAGHER ARTHUR J COM 363576109 3,915 3,915 224 0.0792
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.