Arthur J. Gallagher & Co.
MX ˙ BMV ˙ US3635761097
SecurityMX:AJG / Arthur J. Gallagher & Co.
InstitutionNomura Asset Management Co Ltd
Latest Disclosed Ownership164,861 shares
Latest Disclosed Value $ 35,705,596
Nomura Asset Management Co Ltd reports 5.80% decrease in ownership of AJG / Arthur J. Gallagher & Co.

On May 11, 2026 - Nomura Asset Management Co Ltd filed a 13F-HR form disclosing ownership of 164,861 shares of Arthur J. Gallagher & Co. (MX:AJG) valued at $35,705,596 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 175,016 shares of Arthur J. Gallagher & Co.. This represents a change in shares of -5.80% 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)
2026-05-11 2026-03-31 13F GALLAGHER ARTHUR J COM 363576109 164,861 -10,155 -5.80 35,706 -21.17 0.0576
2026-02-10 2025-12-31 13F GALLAGHER ARTHUR J COM 363576109 175,016 -213,464 -54.95 45,292 -62.36 0.1146
2025-11-12 2025-09-30 13F GALLAGHER ARTHUR J COM 363576109 388,480 54,201 16.21 120,328 12.45 0.3141
2025-08-11 2025-06-30 13F GALLAGHER ARTHUR J COM 363576109 334,279 -45,973 -12.09 107,009 -18.49 0.2934
2025-05-12 2025-03-31 13F GALLAGHER ARTHUR J COM 363576109 380,252 55,893 17.23 131,278 42.59 0.4018
2025-02-12 2024-12-31 13F ARTHUR J GALLAGHER COM 363576109 324,359 479 0.15 92,069 1.03 0.2770
2024-11-15 2024-09-30 13F GALLAGHER ARTHUR J COM 363576109 323,880 262,987 431.88 91,130 477.14 0.2810
2024-08-14 2024-06-30 13F GALLAGHER ARTHUR J COM 363576109 60,893 1,652 2.79 15,790 6.60 0.0538
2024-05-13 2024-03-31 13F GALLAGHER ARTHUR J COM 363576109 59,241 2,406 4.23 14,813 15.89 0.0538
2024-02-09 2023-12-31 13F GALLAGHER ARTHUR J COM 363576109 56,835 -13,128 -18.76 12,781 -19.85 0.0528
2023-11-03 2023-09-30 13F GALLAGHER ARTHUR J COM 363576109 69,963 -146 -0.21 15,947 3.59 0.0747
2023-08-14 2023-06-30 13F GALLAGHER ARTHUR J COM 363576109 70,109 1,241 1.80 15,394 16.83 0.0709
2025-01-10 2023-03-31 13F/A-1 GALLAGHER ARTHUR J COM 363576109 68,868 -1,511 -2.15 13,175 -0.71 0.0692
2023-05-11 2023-03-31 13F GALLAGHER ARTHUR J COM 363576109 68,868 -1,511 13,175 0.0692
2025-01-10 2022-12-31 13F/A-1 GALLAGHER ARTHUR J COM 363576109 70,379 -572 -0.81 13,269 9.23 0.0771
2023-02-14 2022-12-31 13F GALLAGHER ARTHUR J COM 363576109 70,379 -572 13,269 0.0771
2025-01-10 2022-09-30 13F/A-3 GALLAGHER ARTHUR J COM 363576109 70,951 873 1.25 12,148 6.33 0.0773
2022-11-14 2022-09-30 13F/A-2 GALLAGHER ARTHUR J COM 363576109 70,951 873 12,148 0.0773
2022-11-10 2022-09-30 13F/A-1 GALLAGHER ARTHUR J COM 363576109 70,951 873 12,148 0.0773
2022-11-10 2022-09-30 13F GALLAGHER ARTHUR J COM 363576109 70,951 873 12,148 0.0489
2025-01-10 2022-06-30 13F/A-1 GALLAGHER ARTHUR J COM 363576109 70,078 24,111 52.45 11,426 42.37 0.0714
2022-08-12 2022-06-30 13F GALLAGHER ARTHUR J COM 363576109 70,078 24,111 11,426 0.0705
2025-01-10 2022-03-31 13F/A-1 GALLAGHER ARTHUR J COM 363576109 45,967 3,047 7.10 8,026 10.20 0.0437
2022-05-13 2022-03-31 13F GALLAGHER ARTHUR J COM 363576109 45,967 3,047 8,026 0.0437
2025-01-10 2021-12-31 13F/A-2 GALLAGHER ARTHUR J COM 363576109 42,920 941 2.24 7,282 16.70 0.0368
2022-02-01 2021-12-31 13F GALLAGHER ARTHUR J COM 363576109 42,920 941 7,282 0.0368
2025-01-10 2021-09-30 13F/A-2 GALLAGHER ARTHUR J COM 363576109 41,979 3,978 10.47 6,240 17.23 0.0352
2021-11-12 2021-09-30 13F GALLAGHER ARTHUR J COM 363576109 41,979 3,978 6,240 0.0352
2025-01-10 2021-06-30 13F/A-2 GALLAGHER ARTHUR J COM 363576109 38,001 2,324 6.51 5,323 19.59 0.0308
2021-08-06 2021-06-30 13F GALLAGHER ARTHUR J COM 363576109 38,001 2,324 5,323 0.0308
2025-01-10 2021-03-31 13F/A-2 GALLAGHER ARTHUR J COM 363576109 35,677 -161 -0.45 4,451 0.41 0.0284
2021-05-14 2021-03-31 13F GALLAGHER ARTHUR J COM 363576109 35,677 -161 4,451 0.0284
2025-01-10 2020-12-31 13F/A-2 GALLAGHER ARTHUR J COM 363576109 35,838 2,550 7.66 4,434 26.15 0.0298
2021-02-12 2020-12-31 13F GALLAGHER ARTHUR J COM 363576109 35,838 2,550 4,433 0.0298
2020-11-12 2020-09-30 13F GALLAGHER ARTHUR J COM 363576109 33,288 70 0.21 3,514 8.52 0.0270
2020-08-13 2020-06-30 13F GALLAGHER ARTHUR J COM 363576109 33,218 -4,172 -11.16 3,238 6.23 0.0274
2020-05-14 2020-03-31 13F GALLAGHER ARTHUR J COM 363576109 37,390 3,230 9.46 3,048 -6.30 0.0315
2020-02-13 2019-12-31 13F GALLAGHER ARTHUR J COM 363576109 34,160 831 2.49 3,253 8.98 0.0291
2019-11-13 2019-09-30 13F GALLAGHER ARTHUR J COM 363576109 33,329 -3,519 -9.55 2,985 -7.50 0.0285
2019-08-13 2019-06-30 13F GALLAGHER ARTHUR J COM 363576109 36,848 -423 -1.13 3,227 10.86 0.0319
2019-05-10 2019-03-31 13F/A-1 GALLAGHER ARTHUR J COM 363576109 37,271 210 0.57 2,911 6.55 0.0286
2019-05-10 2019-03-31 13F GALLAGHER ARTHUR J COM 363576109 37,271 210 2,911
2019-02-12 2018-12-31 13F GALLAGHER ARTHUR J COM 363576109 37,061 7,442 25.13 2,732 23.96 0.0305
2018-11-07 2018-09-30 13F GALLAGHER ARTHUR J COM 363576109 29,619 1,855 6.68 2,204 21.63 0.0214
2018-08-03 2018-06-30 13F GALLAGHER ARTHUR J COM 363576109 27,764 -309 -1.10 1,812 -6.11 0.0188
2018-05-14 2018-03-31 13F GALLAGHER ARTHUR J COM 363576109 28,073 1,181 4.39 1,930 13.46 0.0211
2018-02-14 2017-12-31 13F GALLAGHER ARTHUR J COM 363576109 26,892 70 0.26 1,701 3.03 0.0197
2017-11-13 2017-09-30 13F GALLAGHER ARTHUR J COM 363576109 26,822 1,961 7.89 1,651 16.02 0.0213
2017-08-14 2017-06-30 13F GALLAGHER ARTHUR J COM 363576109 24,861 2,973 13.58 1,423 14.94 0.0191
2017-06-28 2017-03-31 13F/A-1 GALLAGHER ARTHUR J COM 363576109 21,888 508 2.38 1,238 11.43 0.0174
2017-05-12 2017-03-31 13F GALLAGHER ARTHUR J COM 363576109 22,888 1,295
2017-02-14 2016-12-31 13F GALLAGHER ARTHUR J COM 363576109 21,380 -1,200 -5.31 1,111 -3.31 0.0200
2016-11-10 2016-09-30 13F GALLAGHER ARTHUR J COM 363576109 22,580 1,800 8.66 1,149 16.18 0.0206
2016-08-12 2016-06-30 13F GALLAGHER ARTHUR J COM 363576109 20,780 100 0.48 989 7.50 0.0185
2016-05-13 2016-03-31 13F GALLAGHER ARTHUR J COM 363576109 20,680 2,140 11.54 920 21.21 0.0175
2016-02-12 2015-12-31 13F GALLAGHER ARTHUR J COM 363576109 18,540 1,000 5.70 759 4.83 0.0147
2015-11-13 2015-09-30 13F GALLAGHER ARTHUR J COM 363576109 17,540 700 4.16 724 -9.16 0.0145
2015-08-14 2015-06-30 13F GALLAGHER ARTHUR J COM 363576109 16,840 16,840 0.00 797 0.0147
2014-11-14 2014-09-30 13F GALLAGHER ARTHUR J COM 363576109 0 -195,180 -100.00 0 -100.00
2014-08-14 2014-06-30 13F GALLAGHER ARTHUR J COM 363576109 195,180 -24,800 -11.27 9,095 -13.11 0.1681
2014-05-14 2014-03-31 13F GALLAGHER ARTHUR J COM 363576109 219,980 -2,300 -1.03 10,467 0.34 0.1914
2014-02-14 2013-12-31 13F GALLAGHER ARTHUR J COM 363576109 222,280 -370 -0.17 10,432 7.34 0.1875
2013-11-13 2013-09-30 13F GALLAGHER ARTHUR J COM 363576109 222,650 -1,600 -0.71 9,719 -0.81 0.1840
2013-08-13 2013-06-30 13F GALLAGHER ARTHUR J COM 363576109 224,250 224,250 9,798 0.1942
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.