Amphenol Corporation
US ˙ NYSE ˙ US0320951017

SecurityAPH / Amphenol Corporation
InstitutionMadison Asset Management, LLC
Latest Disclosed Ownership1,251,006 shares
Latest Disclosed Value $ 158,064,598
Madison Asset Management, LLC reports 6.70% decrease in ownership of APH / Amphenol Corporation

On May 7, 2026 - Madison Asset Management, LLC filed a 13F-HR form disclosing ownership of 1,251,006 shares of Amphenol Corporation (US:APH) valued at $158,064,608 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 4, 2026 disclosing 1,340,841 shares of Amphenol Corporation. This represents a change in shares of -6.70% during the quarter. The current value of the position is $173,652,143 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.

Upgrade to unlock premium data and export to Excel .

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 Amphenol COM 032095101 1,251,006 -89,835 -6.70 158,065 -12.77 1.9602
2026-02-04 2025-12-31 13F Amphenol COM 032095101 1,340,841 -1,101,861 -45.11 181,201 -40.06 2.0836
2025-11-06 2025-09-30 13F Amphenol COM 032095101 2,442,702 -35,617 -1.44 302,284 23.52 3.3337
2025-08-11 2025-06-30 13F Amphenol COM 032095101 2,478,319 -68,028 -2.67 244,734 46.54 2.6430
2025-05-06 2025-03-31 13F Amphenol COM 032095101 2,546,347 274,945 12.10 167,015 5.87 1.8608
2025-02-10 2024-12-31 13F Amphenol COM 032095101 2,271,402 195,559 9.42 157,749 16.62 1.7793
2024-11-12 2024-09-30 13F Amphenol COM 032095101 2,075,843 125,037 6.41 135,262 2.92 1.5208
2024-08-09 2024-06-30 13F Amphenol COM 032095101 1,950,806 1,059,751 118.93 131,426 27.87 1.6265
2024-05-09 2024-03-31 13F Amphenol COM 032095101 891,055 86,301 10.72 102,783 28.84 1.2642
2024-02-12 2023-12-31 13F Amphenol COM 032095101 804,754 25,801 3.31 79,775 21.94 1.0810
2023-11-13 2023-09-30 13F Amphenol COM 032095101 778,953 26,362 3.50 65,424 2.33 0.9602
2023-08-01 2023-06-30 13F Amphenol COM 032095101 752,591 -2,156 -0.29 63,933 3.66 0.9328
2023-04-26 2023-03-31 13F Amphenol COM 032095101 754,747 -6,567 -0.86 61,678 108,105.26 0.9368
2023-02-08 2022-12-31 13F Amphenol COM 032095101 761,314 1,750 0.23 58 -99.89 0.9094
2022-11-10 2022-09-30 13F Amphenol COM 032095101 759,564 4,951 0.66 50,860 4.69 0.8574
2022-08-09 2022-06-30 13F Amphenol COM 032095101 754,613 -17,245 -2.23 48,582 -16.47 0.7583
2022-05-12 2022-03-31 13F Amphenol CL A 032095101 771,858 -8,807 -1.13 58,160 -14.82 0.8320
2022-02-15 2021-12-31 13F Amphenol CL A 032095101 780,665 -9,201 -1.16 68,277 18.04 0.8954
2021-11-12 2021-09-30 13F Amphenol CL A 032095101 789,866 -2,012 -0.25 57,842 6.77 0.7959
2021-08-09 2021-06-30 13F Amphenol CL A 032095101 791,878 -7,093 -0.89 54,172 2.78 0.7309
2021-05-11 2021-03-31 13F Amphenol CL A 032095101 798,971 394,576 97.57 52,708 -0.33 0.7352
2021-02-12 2020-12-31 13F Amphenol CL A 032095101 404,395 -1,577 -0.39 52,883 20.31 0.7772
2020-11-12 2020-09-30 13F Amphenol CL A 032095101 405,972 -7,316 -1.77 43,955 11.01 0.7344
2020-08-13 2020-06-30 13F Amphenol CL A 032095101 413,288 -1,455 -0.35 39,597 31.00 0.6945
2020-05-12 2020-03-31 13F Amphenol CL A 032095101 414,743 -6,039 -1.44 30,226 -33.63 0.6209
2020-02-12 2019-12-31 13F Amphenol CL A 032095101 420,782 420,782 45,541 0.6993
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.