Arthur J. Gallagher & Co.
MX ˙ BMV ˙ US3635761097
SecurityMX:AJG / Arthur J. Gallagher & Co.
InstitutionGAMMA Investing LLC
Latest Disclosed Ownership3,673 shares
Latest Disclosed Value $ 795,498
GAMMA Investing LLC reports 7.22% decrease in ownership of AJG / Arthur J. Gallagher & Co.

On April 6, 2026 - GAMMA Investing LLC filed a 13F-HR form disclosing ownership of 3,673 shares of Arthur J. Gallagher & Co. (MX:AJG) valued at $795,498 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 5, 2026 disclosing 3,959 shares of Arthur J. Gallagher & Co.. This represents a change in shares of -7.22% 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)
2026-04-06 2026-03-31 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 3,673 -286 -7.22 795 -22.36 0.0371
2026-01-05 2025-12-31 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 3,959 -1,175 -22.89 1,025 -35.60 0.0515
2025-10-02 2025-09-30 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 5,134 -53 -1.02 1,590 -4.22 0.0877
2025-07-14 2025-06-30 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 5,187 870 20.15 1,660 11.41 0.1050
2025-04-15 2025-03-31 13F/A-1 GALLAGHER ARTHUR J CO COM Common Stock 363576109 4,317 -834 -16.19 1,490 1.92 0.1118
2025-04-07 2025-03-31 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 1,490,401 1,485,250 4 0.0230
2025-01-03 2024-12-31 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 5,151 1,745 51.23 1,462 52.61 0.1246
2024-10-04 2024-09-30 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 3,406 870 958 0.0950
2024-10-07 2024-09-30 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 3,406 870 34.31 958 45.81 0.0950
2024-07-02 2024-06-30 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 2,536 874 52.59 658 58.31 0.0896
2024-04-05 2024-03-31 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 1,662 606 57.39 416 69.39 0.0846
2024-02-01 2023-12-31 13F GALLAGHER ARTHUR J CO COM Common Stock 363576109 1,056 1,056 245 0.0664
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.