Arthur J. Gallagher & Co.
MX ˙ BMV ˙ US3635761097
SecurityMX:AJG / Arthur J. Gallagher & Co.
InstitutionPortfolio Design Labs, LLC
Latest Disclosed Ownership5,193 shares
Latest Disclosed Value $ 1,124,724
Portfolio Design Labs, LLC reports 3.53% increase in ownership of AJG / Arthur J. Gallagher & Co.

On May 11, 2026 - Portfolio Design Labs, LLC filed a 13F-HR form disclosing ownership of 5,193 shares of Arthur J. Gallagher & Co. (MX:AJG) valued at $1,124,724 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 5,016 shares of Arthur J. Gallagher & Co.. This represents a change in shares of 3.53% 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 5,193 177 3.53 1,125 -13.41 0.2000
2026-02-11 2025-12-31 13F GALLAGHER ARTHUR J COM 363576109 5,016 81 1.64 1,298 -15.05 0.2140
2025-11-12 2025-09-30 13F GALLAGHER ARTHUR J COM 363576109 4,935 2,404 94.98 1,529 88.64 0.2625
2025-08-13 2025-06-30 13F GALLAGHER ARTHUR J COM 363576109 2,531 -2,312 -47.74 810 -51.53 0.1591
2025-05-14 2025-03-31 13F GALLAGHER ARTHUR J COM 363576109 4,843 -2,344 -32.61 1,672 -18.09 0.3450
2025-01-29 2024-12-31 13F GALLAGHER ARTHUR J COM 363576109 7,187 -362 -4.80 2,040 -3.95 0.4185
2024-11-08 2024-09-30 13F GALLAGHER ARTHUR J COM 363576109 7,549 -5,836 -43.60 2,124 -38.79 0.5931
2024-08-13 2024-06-30 13F GALLAGHER ARTHUR J COM 363576109 13,385 973 7.84 3,471 11.83 1.0719
2024-05-14 2024-03-31 13F GALLAGHER ARTHUR J COM 363576109 12,412 1,332 12.02 3,103 24.57 1.0431
2024-02-12 2023-12-31 13F GALLAGHER ARTHUR J COM 363576109 11,080 11,080 2,492 0.9435
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.