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

SecurityAJG / Arthur J. Gallagher & Co.
InstitutionInterval Partners, LP
Latest Disclosed Ownership39,336 shares
Latest Disclosed Value $ 8,519,391
Interval Partners, LP reports 66.06% increase in ownership of AJG / Arthur J. Gallagher & Co.

On May 15, 2026 - Interval Partners, LP filed a 13F-HR form disclosing ownership of 39,336 shares of Arthur J. Gallagher & Co. (US:AJG) valued at $8,519,391 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 23,688 shares of Arthur J. Gallagher & Co.. This represents a change in shares of 66.06% during the quarter. The current value of the position is $7,965,540 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)
2026-05-15 2026-03-31 13F GALLAGHER ARTHUR J COM 363576109 39,336 15,648 66.06 8,519 38.97 0.2232
2026-02-17 2025-12-31 13F GALLAGHER ARTHUR J COM 363576109 23,688 -2,864 -10.79 6,130 -25.46 0.1097
2025-11-14 2025-09-30 13F GALLAGHER ARTHUR J COM 363576109 26,552 26,552 8,224 0.1342
2025-05-15 2025-03-31 13F GALLAGHER ARTHUR J COM 363576109 0 -65,623 -100.00 0 -100.00
2025-02-14 2024-12-31 13F GALLAGHER ARTHUR J COM 363576109 65,623 65,623 18,627 0.3657
2024-11-14 2024-09-30 13F GALLAGHER ARTHUR J COM 363576109 0 -3,194 -100.00 0 -100.00
2024-08-14 2024-06-30 13F GALLAGHER ARTHUR J COM 363576109 3,194 3,194 828 0.0181
2022-11-14 2022-09-30 13F GALLAGHER ARTHUR J COM 363576109 0 -13,399 -100.00 0 -100.00
2022-08-15 2022-06-30 13F GALLAGHER ARTHUR J COM 363576109 13,399 -10,497 -43.93 2,185 -47.63 0.1130
2022-05-16 2022-03-31 13F GALLAGHER ARTHUR J COM 363576109 23,896 4,188 21.25 4,172 24.76 0.2030
2022-02-14 2021-12-31 13F GALLAGHER ARTHUR J COM 363576109 19,708 -15,792 -44.48 3,344 -36.63 0.1428
2021-11-15 2021-09-30 13F GALLAGHER ARTHUR J COM 363576109 35,500 21,554 154.55 5,277 170.06 0.2135
2021-08-16 2021-06-30 13F GALLAGHER ARTHUR J COM 363576109 13,946 -26,854 -65.82 1,954 -61.62 0.0807
2021-05-17 2021-03-31 13F GALLAGHER ARTHUR J COM 363576109 40,800 40,800 5,091 0.1966
2021-02-25 2020-12-31 13F/A-1 GALLAGHER ARTHUR J COM 363576109 0 -49,800 -100.00 0 -100.00
2020-11-16 2020-09-30 13F GALLAGHER ARTHUR J COM 363576109 49,800 35,531 249.01 5,258 278.00 0.2956
2020-08-14 2020-06-30 13F GALLAGHER ARTHUR J COM 363576109 14,269 -731 -4.87 1,391 13.74 0.0879
2020-05-15 2020-03-31 13F GALLAGHER ARTHUR J COM 363576109 15,000 15,000 1,223 0.0940
2019-02-14 2018-12-31 13F GALLAGHER ARTHUR J COM 363576109 0 -30,825 -100.00 0 -100.00
2018-11-14 2018-09-30 13F GALLAGHER ARTHUR J COM 363576109 30,825 -103,550 -77.06 2,295 -73.84 0.0937
2018-08-14 2018-06-30 13F GALLAGHER ARTHUR J COM 363576109 134,375 134,375 8,772 0.3258
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.