Arthur J. Gallagher & Co.
MX ˙ BMV ˙ US3635761097
SecurityMX:AJG / Arthur J. Gallagher & Co.
InstitutionProspector Partners Llc
Latest Disclosed Ownership3,120 shares
Latest Disclosed Value $ 807,425
Prospector Partners Llc reports 93.06% decrease in ownership of AJG / Arthur J. Gallagher & Co.

On February 13, 2026 - Prospector Partners Llc filed a 13F-HR form disclosing ownership of 3,120 shares of Arthur J. Gallagher & Co. (MX:AJG) valued at $807,425 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 7, 2025 disclosing 44,964 shares of Arthur J. Gallagher & Co.. This represents a change in shares of -93.06% 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)
2026-02-13 2025-12-31 13F GALLAGHER ARTHUR J COM 363576109 3,120 -41,844 -93.06 807 -94.21
2025-11-07 2025-09-30 13F GALLAGHER ARTHUR J COM 363576109 44,964 -32,699 -42.10 13,927 -43.98 1.6641
2025-08-08 2025-06-30 13F GALLAGHER ARTHUR J COM 363576109 77,663 -3,089 -3.83 24,861 -10.82 2.8418
2025-05-13 2025-03-31 13F GALLAGHER ARTHUR J COM 363576109 80,752 -387 -0.48 27,879 21.05 3.1416
2025-02-13 2024-12-31 13F GALLAGHER ARTHUR J COM 363576109 81,139 175 0.22 23,031 1.10 2.5552
2024-11-13 2024-09-30 13F GALLAGHER ARTHUR J COM 363576109 80,964 257 0.32 22,781 8.85 2.3833
2024-08-13 2024-06-30 13F GALLAGHER ARTHUR J COM 363576109 80,707 443 0.55 20,928 4.28 2.3394
2024-05-09 2024-03-31 13F GALLAGHER ARTHUR J COM 363576109 80,264 -20,290 -20.18 20,069 -11.25 2.2066
2024-02-09 2023-12-31 13F GALLAGHER ARTHUR J COM 363576109 100,554 280 0.28 22,613 -1.06 2.8237
2023-11-13 2023-09-30 13F GALLAGHER ARTHUR J COM 363576109 100,274 375 0.38 22,855 4.20 3.0772
2023-08-10 2023-06-30 13F GALLAGHER ARTHUR J COM 363576109 99,899 550 0.55 21,935 15.41 3.0606
2023-05-08 2023-03-31 13F GALLAGHER ARTHUR J COM 363576109 99,349 -12,024 -10.80 19,006 -9.49 2.6438
2023-02-15 2022-12-31 13F GALLAGHER ARTHUR J COM 363576109 111,373 348 0.31 20,998 10.46 2.8716
2022-11-10 2022-09-30 13F GALLAGHER ARTHUR J COM 363576109 111,025 9,175 9.01 19,010 14.48 2.8302
2022-08-11 2022-06-30 13F GALLAGHER ARTHUR J COM 363576109 101,850 -3,795 -3.59 16,606 -9.98 2.4181
2022-05-12 2022-03-31 13F GALLAGHER ARTHUR J COM 363576109 105,645 -9,780 -8.47 18,446 -5.81 2.2807
2022-02-11 2021-12-31 13F GALLAGHER ARTHUR J COM 363576109 115,425 -10,375 -8.25 19,584 4.73 2.2641
2021-11-10 2021-09-30 13F GALLAGHER ARTHUR J COM 363576109 125,800 -2,000 -1.56 18,700 4.46 2.4013
2021-08-11 2021-06-30 13F GALLAGHER ARTHUR J COM 363576109 127,800 1,000 0.79 17,902 13.15 2.2539
2021-05-13 2021-03-31 13F GALLAGHER ARTHUR J COM 363576109 126,800 -71,050 -35.91 15,821 -35.36 2.0236
2021-02-11 2020-12-31 13F GALLAGHER ARTHUR J COM 363576109 197,850 -12,250 -5.83 24,476 10.34 3.0428
2020-11-13 2020-09-30 13F GALLAGHER ARTHUR J COM 363576109 210,100 21,050 11.13 22,182 20.36 3.3350
2020-08-14 2020-06-30 13F GALLAGHER ARTHUR J COM 363576109 189,050 46,500 32.62 18,430 58.62 3.2054
2020-05-13 2020-03-31 13F GALLAGHER ARTHUR J COM 363576109 142,550 54,150 61.26 11,619 38.03 2.1948
2020-02-13 2019-12-31 13F GALLAGHER ARTHUR J COM 363576109 88,400 29,600 50.34 8,418 59.83 1.1818
2019-11-13 2019-09-30 13F GALLAGHER ARTHUR J COM 363576109 58,800 -3,700 -5.92 5,267 -3.78 0.7698
2019-08-14 2019-06-30 13F GALLAGHER ARTHUR J COM 363576109 62,500 -30,000 -32.43 5,474 24.38 0.7507
2014-05-15 2014-03-31 13F GALLAGHER ARTHUR J COM 363576109 92,500 0 0.00 4,401 1.38 0.2097
2014-02-14 2013-12-31 13F GALLAGHER ARTHUR J COM 363576109 92,500 -2,300 -2.43 4,341 4.91 0.1931
2013-11-14 2013-09-30 13F GALLAGHER ARTHUR J COM 363576109 94,800 0 0.00 4,138 -0.10 0.1881
2013-08-12 2013-06-30 13F GALLAGHER ARTHUR J COM 363576109 94,800 94,800 4,142 0.2041
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.