Arthur J. Gallagher & Co.
US ˙ NYSE ˙ US3635761097

SecurityAJG / Arthur J. Gallagher & Co.
InstitutionMather Group, Llc.
Latest Disclosed Ownership1,458 shares
Latest Disclosed Value $ 315,713
Mather Group, Llc. reports 39.45% decrease in ownership of AJG / Arthur J. Gallagher & Co.

On April 13, 2026 - Mather Group, Llc. filed a 13F-HR form disclosing ownership of 1,458 shares of Arthur J. Gallagher & Co. (US:AJG) valued at $315,774 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 13, 2026 disclosing 2,408 shares of Arthur J. Gallagher & Co.. This represents a change in shares of -39.45% during the quarter. The current value of the position is $307,638 USD.

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)
2026-04-13 2026-03-31 13F GALLAGHER ARTHUR J COM 363576109 1,458 -950 -39.45 316 -49.44 0.0031
2026-01-13 2025-12-31 13F GALLAGHER ARTHUR J COM 363576109 2,408 55 2.34 623 -14.42 0.0064
2025-10-21 2025-09-30 13F GALLAGHER ARTHUR J COM 363576109 2,353 6 0.26 729 -3.06 0.0074
2025-07-15 2025-06-30 13F GALLAGHER ARTHUR J COM 363576109 2,347 -91 -3.73 751 -10.70 0.0080
2025-04-25 2025-03-31 13F GALLAGHER ARTHUR J COM 363576109 2,438 58 2.44 842 24.59 0.0097
2025-01-27 2024-12-31 13F GALLAGHER ARTHUR J COM 363576109 2,380 17 0.72 676 1.50 0.0088
2024-10-07 2024-09-30 13F GALLAGHER ARTHUR J COM 363576109 2,363 -254 -9.71 665 1.68 0.0085
2024-07-09 2024-06-30 13F GALLAGHER ARTHUR J COM 363576109 2,617 478 22.35 654 35.97 0.0081
2024-04-09 2024-03-31 13F GALLAGHER ARTHUR J COM 363576109 2,139 -389 -15.39 481 -15.32 0.0076
2024-02-05 2023-12-31 13F GALLAGHER ARTHUR J COM 363576109 2,528 409 19.30 568 17.60 0.0089
2023-11-13 2023-09-30 13F GALLAGHER ARTHUR J COM 363576109 2,119 117 5.84 483 10.02 0.0086
2023-08-08 2023-06-30 13F GALLAGHER ARTHUR J COM 363576109 2,002 520 35.09 440 55.12 0.0070
2023-05-09 2023-03-31 13F GALLAGHER ARTHUR J COM 363576109 1,482 -8 -0.54 284 1.07 0.0050
2023-03-10 2022-12-31 13F GALLAGHER ARTHUR J COM 363576109 1,490 1,490 281 0.0054
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.