Aon plc
US ˙ NYSE ˙ IE00BLP1HW54

SecurityAON / Aon plc
InstitutionDimensional Fund Advisors Lp
Latest Disclosed Ownership1,253,769 shares
Latest Disclosed Value $ 404,709,376
Dimensional Fund Advisors Lp reports 20.47% increase in ownership of AON / Aon plc

On May 7, 2026 - Dimensional Fund Advisors Lp filed a 13F-HR form disclosing ownership of 1,253,769 shares of Aon plc (US:AON) valued at $404,691,558 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 1,040,718 shares of Aon plc. This represents a change in shares of 20.47% during the quarter. The current value of the position is $411,900,730 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)
2026-05-07 2026-03-31 13F AON SHS CL A G0403H108 1,253,769 213,051 20.47 404,709 10.19 0.0181
2026-02-12 2025-12-31 13F AON SHS CL A G0403H108 1,040,718 96,885 10.27 367,290 9.14 0.0770
2025-11-12 2025-09-30 13F AON SHS CL A G0403H108 943,833 47,335 5.28 336,529 5.23 0.0722
2025-08-12 2025-06-30 13F AON SHS CL A G0403H108 896,498 83,785 10.31 319,794 -1.39 0.0740
2025-05-13 2025-03-31 13F AON SHS CL A G0403H108 812,713 75,797 10.29 324,309 22.53 0.0806
2025-02-13 2024-12-31 13F AON SHS CL A G0403H108 736,916 70,137 10.52 264,667 14.72 0.0636
2024-11-07 2024-09-30 13F AON SHS CL A G0403H108 666,779 10,835 1.65 230,709 19.81 0.0560
2024-08-09 2024-06-30 13F AON SHS CL A G0403H108 655,944 46,560 7.64 192,568 -5.31 0.0503
2024-05-10 2024-03-31 13F AON SHS CL A G0403H108 609,384 -156,153 -20.40 203,364 -8.71 0.0551
2024-02-07 2023-12-31 13F AON SHS CL A G0403H108 765,537 5,770 0.76 222,777 -9.58 0.0651
2023-11-09 2023-09-30 13F AON SHS CL A G0403H108 759,767 4,806 0.64 246,371 -5.46 0.0808
2023-08-09 2023-06-30 13F AON SHS CL A G0403H108 754,961 -46,570 -5.81 260,604 3.13 0.0831
2023-05-12 2023-03-31 13F AON SHS CL A G0403H108 801,531 -129,567 -13.92 252,704 90,474.91 0.0851
2023-02-09 2022-12-31 13F AON SHS CL A G0403H108 931,098 -63,727 -6.41 279 -99.90 0.0826
2022-11-10 2022-09-30 13F AON SHS CL A G0403H108 994,825 4,557 0.46 266,508 -0.20 0.1023
2022-08-12 2022-06-30 13F AON SHS CL A G0403H108 990,268 -84,618 -7.87 267,034 -23.71 0.0958
2022-05-13 2022-03-31 13F AON CLA G0403H108 1,074,886 -86,021 -7.41 350,022 0.32 0.1078
2022-02-09 2021-12-31 13F AON CLA G0403H108 1,160,907 -28,620 -2.41 348,912 2.63 0.1055
2021-11-12 2021-09-30 13F AON CLA G0403H108 1,189,527 7,273 0.62 339,982 20.43 0.1095
2021-08-12 2021-06-30 13F AON CLA G0403H108 1,182,254 109,742 10.23 282,308 14.38 0.0894
2021-05-14 2021-03-31 13F AON CLA G0403H108 1,072,512 23,796 2.27 246,813 11.42 0.0816
2021-03-08 2020-12-31 13F/A-2 AON CLA G0403H108 1,048,716 109,239 11.63 221,525 14.31 0.0800
2021-02-11 2020-12-31 13F AON CLA G0403H108 1,048,716 109,239 221,525 80,003.0553
2020-11-12 2020-09-30 13F AON CLA G0403H108 939,477 45,339 5.07 193,799 12.56 0.0822
2020-08-13 2020-06-30 13F AON CLA G0403H108 894,138 57,628 6.89 172,175 24.67 0.0757
2020-05-14 2020-03-31 13F AON CLA G0408V102 836,510 40,414 5.08 138,102 -16.71 0.0719
2020-02-14 2019-12-31 13F AON CLA G0408V102 796,096 5,287 0.67 165,815 8.32 0.0604
2019-11-12 2019-09-30 13F AON CLA G0408V102 790,809 52,349 7.09 153,078 7.42 0.0595
2019-08-13 2019-06-30 13F AON CLA G0408V102 738,460 15,456 2.14 142,508 15.47 0.0553
2019-08-12 2019-03-31 13F/A-2 AON CLA G0408V102 723,004 23,854 3.41 123,411 21.44 0.0492
2019-05-10 2019-03-31 13F AON CLA G0408V102 723,004 23,854 123,411
2019-02-26 2018-12-31 13F/A-1 AON CLA G0408V102 699,150 40,993 6.23 101,623 0.40 0.0460
2019-02-13 2018-12-31 13F AON CLA G0408V102 699,150 40,993 101,623
2018-11-13 2018-09-30 13F AON CLA G0408V102 658,157 4,070 0.62 101,220 12.82 0.0385
2018-08-10 2018-06-30 13F AON CLA G0408V102 654,087 10,248 1.59 89,718 -0.70 0.0358
2018-05-11 2018-03-31 13F AON CLA G0408V102 643,839 -3,645 -0.56 90,350 4.13 0.0377
2018-02-12 2017-12-31 13F AON CLA G0408V102 647,484 -15,043 -2.27 86,767 -10.36 0.0360
2017-11-13 2017-09-30 13F AON CLA G0408V102 662,527 -2,821 -0.42 96,799 9.43 0.0423
2017-08-11 2017-06-30 13F AON CLA G0408V102 665,348 6,515 0.99 88,459 13.13 0.0408
2017-05-12 2017-03-31 13F AON CLA G0408V102 658,833 30,970 4.93 78,195 11.67 0.0374
2017-02-09 2016-12-31 13F AON CLA G0408V102 627,863 3,186 0.51 70,026 -0.34 0.0350
2016-11-10 2016-09-30 13F AON CLA G0408V102 624,677 25,067 4.18 70,263 7.30 0.0380
2016-08-09 2016-06-30 13F AON CLA G0408V102 599,610 17,920 3.08 65,485 7.79 0.0377
2016-05-13 2016-03-31 13F AON CLA G0408V102 581,690 34,519 6.31 60,755 20.40 0.0364
2016-02-10 2015-12-31 13F AON CLA G0408V102 547,171 10,357 1.93 50,460 6.08 0.0315
2015-11-13 2015-09-30 13F AON CLA G0408V102 536,814 44,121 8.96 47,570 -3.15 0.0312
2015-08-14 2015-06-30 13F AON CLA G0408V102 492,693 6,223 1.28 49,115 5.03 0.0301
2015-05-14 2015-03-31 13F AON CLA G0408V102 486,470 1,659 0.34 46,765 1.71 0.0295
2015-02-06 2014-12-31 13F AON CLA G0408V102 484,811 6,960 1.46 45,981 9.76 0.0302
2014-11-13 2014-09-30 13F AON CLA G0408V102 477,851 -21,463 -4.30 41,894 -6.87 0.0297
2014-08-08 2014-06-30 13F AON CLA G0408V102 499,314 371 0.07 44,984 7.00 0.0313
2014-05-14 2014-03-31 13F AON CLA G0408V102 498,943 1,091 0.22 42,043 0.67 0.0314
2014-02-12 2013-12-31 13F AON CLA G0408V102 497,852 -9,055 -1.79 41,762 10.67 0.0325
2013-11-13 2013-09-30 13F AON CLA G0408V102 506,907 528 0.10 37,735 15.79 0.0327
2013-08-15 2013-06-30 13F AON CLA G0408V102 506,379 506,379 32,589 0.0307
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.