Arthur J. Gallagher & Co.
MX ˙ BMV ˙ US3635761097
SecurityMX:AJG / Arthur J. Gallagher & Co.
InstitutionOppenheimer & Co Inc
Latest Disclosed Ownership5,829 shares
Latest Disclosed Value $ 1,262,445
Oppenheimer & Co Inc reports 14.76% decrease in ownership of AJG / Arthur J. Gallagher & Co.

On April 23, 2026 - Oppenheimer & Co Inc filed a 13F-HR form disclosing ownership of 5,829 shares of Arthur J. Gallagher & Co. (MX:AJG) valued at $1,262,445 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 2, 2026 disclosing 6,838 shares of Arthur J. Gallagher & Co.. This represents a change in shares of -14.76% 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)
2026-04-23 2026-03-31 13F GALLAGHER ARTHUR J COM 363576109 5,829 -1,009 -14.76 1,262 -28.66 0.0154
2026-02-02 2025-12-31 13F GALLAGHER ARTHUR J COM 363576109 6,838 1 0.01 1,770 -16.44 0.0251
2025-11-06 2025-09-30 13F GALLAGHER ARTHUR J COM 363576109 6,837 31 0.46 2,118 -2.80 0.0258
2025-07-31 2025-06-30 13F GALLAGHER ARTHUR J COM 363576109 6,806 -348 -4.86 2,179 -11.79 0.0288
2025-04-23 2025-03-31 13F GALLAGHER ARTHUR J COM 363576109 7,154 113 1.60 2,470 23.57 0.0373
2025-02-05 2024-12-31 13F GALLAGHER ARTHUR J COM 363576109 7,041 -29 -0.41 1,999 0.45 0.0298
2024-11-05 2024-09-30 13F GALLAGHER ARTHUR J COM 363576109 7,070 -62 -0.87 1,989 7.57 0.0303
2024-08-08 2024-06-30 13F GALLAGHER ARTHUR J COM 363576109 7,132 372 5.50 1,849 9.41 0.0294
2024-05-07 2024-03-31 13F GALLAGHER ARTHUR J COM 363576109 6,760 -2,108 -23.77 1,690 -15.25 0.0280
2024-02-13 2023-12-31 13F GALLAGHER ARTHUR J COM 363576109 8,868 476 5.67 1,994 4.29 0.0366
2023-11-08 2023-09-30 13F GALLAGHER ARTHUR J COM 363576109 8,392 -258 -2.98 1,913 0.68 0.0395
2023-08-03 2023-06-30 13F GALLAGHER ARTHUR J COM 363576109 8,650 -204 -2.30 1,899 12.17 0.0380
2023-05-10 2023-03-31 13F GALLAGHER ARTHUR J COM 363576109 8,854 108 1.23 1,694 2.73 0.0359
2023-02-08 2022-12-31 13F GALLAGHER ARTHUR J COM 363576109 8,746 -181 -2.03 1,649 7.85 0.0375
2022-11-14 2022-09-30 13F GALLAGHER ARTHUR J COM 363576109 8,927 -554 -5.84 1,528 -1.16 0.0357
2022-08-08 2022-06-30 13F GALLAGHER ARTHUR J COM 363576109 9,481 201 2.17 1,546 -4.57 0.0333
2022-05-12 2022-03-31 13F GALLAGHER ARTHUR J COM 363576109 9,280 54 0.59 1,620 3.51 0.0292
2022-02-02 2021-12-31 13F GALLAGHER ARTHUR J COM 363576109 9,226 143 1.57 1,565 15.93 0.0274
2021-11-12 2021-09-30 13F GALLAGHER ARTHUR J COM 363576109 9,083 671 7.98 1,350 14.60 0.0253
2021-08-03 2021-06-30 13F GALLAGHER ARTHUR J COM 363576109 8,412 -664 -7.32 1,178 4.06 0.0211
2021-05-10 2021-03-31 13F GALLAGHER ARTHUR J COM 363576109 9,076 -582 -6.03 1,132 -5.27 0.0226
2021-02-11 2020-12-31 13F GALLAGHER ARTHUR J COM 363576109 9,658 154 1.62 1,195 19.14 0.0252
2020-11-13 2020-09-30 13F GALLAGHER ARTHUR J COM 363576109 9,504 -1,117 -10.52 1,003 -3.09 0.0251
2020-08-11 2020-06-30 13F GALLAGHER ARTHUR J COM 363576109 10,621 -250 -2.30 1,035 16.82 0.0268
2020-05-08 2020-03-31 13F GALLAGHER ARTHUR J COM 363576109 10,871 -340 -3.03 886 -17.04 0.0269
2020-02-07 2019-12-31 13F GALLAGHER ARTHUR J COM 363576109 11,211 49 0.44 1,068 6.80 0.0264
2019-10-31 2019-09-30 13F GALLAGHER ARTHUR J COM 363576109 11,162 46 0.41 1,000 2.67 0.0272
2019-08-09 2019-06-30 13F GALLAGHER ARTHUR J COM 363576109 11,116 -130 -1.16 974 10.93 0.0265
2019-04-24 2019-03-31 13F GALLAGHER ARTHUR J COM 363576109 11,246 116 1.04 878 7.07 0.0235
2019-01-29 2018-12-31 13F GALLAGHER ARTHUR J COM 363576109 11,130 -12,932 -53.74 820 -54.22 0.0256
2018-10-26 2018-09-30 13F GALLAGHER ARTHUR J COM 363576109 24,062 394 1.66 1,791 15.92 0.0456
2018-08-10 2018-06-30 13F GALLAGHER ARTHUR J COM 363576109 23,668 -480 -1.99 1,545 -6.93 0.0419
2018-05-01 2018-03-31 13F GALLAGHER ARTHUR J COM 363576109 24,148 263 1.10 1,660 9.86 0.0426
2018-02-07 2017-12-31 13F GALLAGHER ARTHUR J COM 363576109 23,885 3,443 16.84 1,511 20.11 0.0389
2017-11-09 2017-09-30 13F GALLAGHER ARTHUR J COM 363576109 20,442 -218 -1.06 1,258 6.34 0.0337
2017-08-09 2017-06-30 13F GALLAGHER ARTHUR J COM 363576109 20,660 -294 -1.40 1,183 -0.17 0.0326
2017-05-15 2017-03-31 13F GALLAGHER ARTHUR J COM 363576109 20,954 -2,696 -11.40 1,185 -3.58 0.0335
2017-02-01 2016-12-31 13F GALLAGHER ARTHUR J COM 363576109 23,650 798 3.49 1,229 5.77 0.0358
2016-11-07 2016-09-30 13F GALLAGHER ARTHUR J COM 363576109 22,852 925 4.22 1,162 11.30 0.0339
2016-08-08 2016-06-30 13F GALLAGHER ARTHUR J COM 363576109 21,927 6,926 46.17 1,044 56.52 0.0311
2016-04-26 2016-03-31 13F GALLAGHER ARTHUR J COM 363576109 15,001 7,455 98.79 667 115.86 0.0203
2016-02-03 2015-12-31 13F GALLAGHER ARTHUR J COM 363576109 7,546 -626 -7.66 309 -8.31 0.0092
2015-11-13 2015-09-30 13F GALLAGHER ARTHUR J COM 363576109 8,172 -95 -1.15 337 -13.81 0.0102
2015-08-12 2015-06-30 13F GALLAGHER ARTHUR J COM 363576109 8,267 350 4.42 391 5.68 0.0109
2015-05-08 2015-03-31 13F GALLAGHER ARTHUR J COM 363576109 7,917 -41 -0.52 370 -1.33 0.0101
2015-02-10 2014-12-31 13F GALLAGHER ARTHUR J COM 363576109 7,958 115 1.47 375 5.34 0.0108
2014-11-12 2014-09-30 13F GALLAGHER ARTHUR J COM 363576109 7,843 11 0.14 356 -2.47 0.0106
2014-08-14 2014-06-30 13F GALLAGHER ARTHUR J COM 363576109 7,832 478 6.50 365 4.29 0.0110
2014-05-09 2014-03-31 13F GALLAGHER ARTHUR J COM 363576109 7,354 943 14.71 350 16.28 0.0105
2014-02-12 2013-12-31 13F GALLAGHER ARTHUR J COM 363576109 6,411 108 1.71 301 9.45 0.0096
2013-11-01 2013-09-30 13F GALLAGHER ARTHUR J COM 363576109 6,303 539 9.35 275 9.13 0.0097
2013-08-14 2013-06-30 13F GALLAGHER ARTHUR J & COM 363576109 5,764 5,764 252 0.0097
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.