Arthur J. Gallagher & Co.
MX ˙ BMV ˙ US3635761097
SecurityMX:AJG / Arthur J. Gallagher & Co.
InstitutionLord, Abbett & Co. Llc
Latest Disclosed Ownership553,552 shares
Latest Disclosed Value $ 119,888
Lord, Abbett & Co. Llc reports 3.41% increase in ownership of AJG / Arthur J. Gallagher & Co.

On May 14, 2026 - Lord, Abbett & Co. Llc filed a 13F-HR form disclosing ownership of 553,552 shares of Arthur J. Gallagher & Co. (MX:AJG) valued at $119,888 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 535,322 shares of Arthur J. Gallagher & Co.. This represents a change in shares of 3.41% 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)
2026-05-14 2026-03-31 13F GALLAGHER ARTHUR J COM 363576109 553,552 18,230 3.41 120 -13.77 0.3914
2026-02-13 2025-12-31 13F GALLAGHER ARTHUR J COM 363576109 535,322 -9,783 -1.79 139 -17.86 0.4250
2025-11-13 2025-09-30 13F GALLAGHER ARTHUR J COM 363576109 545,105 -36,112 -6.21 169 -9.68 0.5027
2025-08-14 2025-06-30 13F GALLAGHER ARTHUR J COM 363576109 581,217 -72,871 -11.14 186 -17.33 0.5986
2025-05-13 2025-03-31 13F GALLAGHER ARTHUR J COM 363576109 654,088 83,069 14.55 226 38.89 0.8044
2025-02-14 2024-12-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 571,019 134,004 30.66 162 32.79 0.5126
2024-12-13 2024-09-30 13F/A-1 Arthur J Gallagher COM 363576109 437,015 -6,376 -1.44 123 7.02 0.3913
2024-11-14 2024-09-30 13F Arthur J Gallagher COM 363576109 437,015 -6,376 123 0.3964
2024-10-07 2024-06-30 13F/A-1 Arthur J Gallagher COM 363576109 443,391 38,857 9.61 115 12.87 0.3761
2024-08-14 2024-06-30 13F Arthur J Gallagher COM 363576109 443,391 38,857 115 0.3840
2024-10-07 2024-03-31 13F/A-1 Arthur J Gallagher COM 363576109 404,534 -11,001 -2.65 101 8.60 0.3265
2024-05-09 2024-03-31 13F Arthur J Gallagher COM 363576109 404,534 -11,001 101 0.3324
2024-10-07 2023-12-31 13F/A-1 Arthur J Gallagher COM 363576109 415,535 -179,871 -30.21 93 -31.11 0.3279
2024-02-12 2023-12-31 13F Arthur J Gallagher COM 363576109 415,535 -179,871 93 0.3356
2024-10-07 2023-09-30 13F/A-1 Arthur J Gallagher COM 363576109 595,406 82,854 16.16 136 20.54 0.5046
2023-11-13 2023-09-30 13F Arthur J Gallagher COM 363576109 595,406 82,854 136 0.5085
2024-10-07 2023-06-30 13F/A-1 Arthur J Gallagher COM 363576109 512,552 -35,877 -6.54 113 7.69 0.3874
2023-08-14 2023-06-30 13F Arthur J Gallagher COM 363576109 512,552 -35,877 113 0.3875
2024-10-07 2023-03-31 13F/A-1 Arthur J Gallagher COM 363576109 548,429 -69,869 -11.30 105 -10.34 0.3783
2023-05-12 2023-03-31 13F Arthur J Gallagher COM 363576109 548,429 -69,869 105 0.3789
2024-10-07 2022-12-31 13F/A-1 Arthur J Gallagher COM 363576109 618,298 -248,385 -28.66 117 -99.92 0.4166
2023-02-10 2022-12-31 13F Arthur J Gallagher COM 363576109 618,298 -248,385 117 0.4175
2022-11-14 2022-09-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 866,683 -37,340 -4.13 148,393 0.68 0.5420
2022-08-12 2022-06-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 904,023 9,513 1.06 147,393 -5.63 0.5211
2022-05-13 2022-03-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 894,510 139,276 18.44 156,179 21.88 0.4163
2022-02-11 2021-12-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 755,234 755,234 128,141 0.2919
2020-02-14 2019-12-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 0 -632,600 -100.00 0 -100.00
2019-11-14 2019-09-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 632,600 -10,400 -1.62 56,662 0.61 0.1929
2019-08-14 2019-06-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 643,000 4,300 0.67 56,320 12.91 0.1830
2019-05-15 2019-03-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 638,700 -211,999 -24.92 49,882 -20.44 0.1661
2019-02-14 2018-12-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 850,699 650,199 324.29 62,697 320.08 0.2289
2018-11-14 2018-09-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 200,500 -481,000 -70.58 14,925 -66.45 0.0414
2018-08-14 2018-06-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 681,500 275,400 67.82 44,488 59.39 0.1300
2018-05-15 2018-03-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 406,100 -58,000 -12.50 27,911 -4.96 0.0829
2018-02-14 2017-12-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 464,100 -137,500 -22.86 29,368 -20.69 0.0836
2017-11-14 2017-09-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 601,600 198,000 49.06 37,028 60.25 0.1081
2017-08-24 2017-06-30 13F/A-1 GALLAGHER ARTHUR J & CO COM COM 363576109 403,600 334,200 481.56 23,106 488.84 0.0686
2017-08-14 2017-06-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 403,600 334,200 23,106
2017-05-15 2017-03-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 69,400 69,400 3,924 0.0117
2016-08-12 2016-06-30 13F GALLAGHER ARTHUR J & CO COM COM 363576109 0 -450,400 -100.00 0 -100.00
2016-05-16 2016-03-31 13F GALLAGHER ARTHUR J & CO COM COM 363576109 450,400 450,400 20,034 0.0630
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.