Amkor Technology, Inc.
US ˙ NasdaqGS ˙ US0316521006

SecurityAMKR / Amkor Technology, Inc.
InstitutionDimensional Fund Advisors Lp
Latest Disclosed Ownership10,991,469 shares
Ownership 4.40%
Dimensional Fund Advisors Lp ownership in AMKR / Amkor Technology, Inc.

2026-04-09 - Dimensional Fund Advisors Lp has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 10,991,469 shares of Amkor Technology, Inc. (US:AMKR). This represents 4.4 percent ownership of the company. In their previous filing dated 2024-02-09 , Dimensional Fund Advisors Lp had reported owning 14,862,198 shares, indicating a decrease of -26.04 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date		Effective
Date		Form Prev
Shares		 Latest
Shares		 ΔShares
(Percent)		 Ownership
(Percent)		 ΔOwnership
(Percent)
2026-04-09 2026-04-09 13G/A 14,862,198 10,991,469 -26.04 4.40 -26.67
2024-02-09 2024-02-09 13G/A 15,711,184 14,862,198 -5.40 6.00 -6.25
2023-02-10 2023-02-10 13G/A 15,417,333 15,711,184 1.91 6.40 1.59
2022-02-08 2022-02-08 13G/A 16,722,945 15,417,333 -7.81 6.30 -8.70
2021-02-12 2021-02-12 13G/A 18,052,461 16,722,945 -7.36 6.90 -8.37
2020-02-12 2020-02-12 13G/A 17,422,753 18,052,461 3.61 7.53 3.58
2019-02-08 2019-02-08 13G/A 15,021,087 17,422,753 15.99 7.27 15.76
2018-02-09 2018-02-09 13G 15,021,087 6.28

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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 AMKOR TECHNOLOGY COM 031652100 10,991,469 -1,781,422 -13.95 494,879 -1.87 0.0222
2026-02-12 2025-12-31 13F AMKOR TECHNOLOGY COM 031652100 12,772,891 -378,319 -2.88 504,287 35.02 0.1058
2025-11-12 2025-09-30 13F AMKOR TECHNOLOGY COM 031652100 13,151,210 -126,575 -0.95 373,495 34.01 0.0801
2025-08-12 2025-06-30 13F AMKOR TECHNOLOGY COM 031652100 13,277,785 -120,645 -0.90 278,705 15.18 0.0645
2025-05-13 2025-03-31 13F AMKOR TECHNOLOGY COM 031652100 13,398,430 365,975 2.81 241,980 -27.73 0.0601
2025-02-13 2024-12-31 13F AMKOR TECHNOLOGY COM 031652100 13,032,455 -366,971 -2.74 334,809 -18.35 0.0804
2024-11-07 2024-09-30 13F AMKOR TECHNOLOGY COM 031652100 13,399,426 -820,019 -5.77 410,029 -27.94 0.0995
2024-08-09 2024-06-30 13F AMKOR TECHNOLOGY COM 031652100 14,219,445 -268,059 -1.85 569,049 21.83 0.1486
2024-05-10 2024-03-31 13F AMKOR TECHNOLOGY COM 031652100 14,487,504 -373,081 -2.51 467,077 -5.53 0.1265
2024-02-07 2023-12-31 13F AMKOR TECHNOLOGY COM 031652100 14,860,585 244,026 1.67 494,421 49.67 0.1444
2023-11-09 2023-09-30 13F AMKOR TECHNOLOGY COM 031652100 14,616,559 -109,540 -0.74 330,341 -24.60 0.1083
2023-08-09 2023-06-30 13F AMKOR TECHNOLOGY COM 031652100 14,726,099 -200,816 -1.35 438,104 12.80 0.1396
2023-05-12 2023-03-31 13F AMKOR TECHNOLOGY COM 031652100 14,926,915 -784,269 -4.99 388,397 103,197.07 0.1308
2023-02-09 2022-12-31 13F AMKOR TECHNOLOGY COM 031652100 15,711,184 51,306 0.33 377 -99.86 0.1113
2022-11-10 2022-09-30 13F AMKOR TECHNOLOGY COM 031652100 15,659,878 145,752 0.94 266,995 1.54 0.1025
2022-08-12 2022-06-30 13F AMKOR TECHNOLOGY COM 031652100 15,514,126 179,540 1.17 262,955 -21.05 0.0943
2022-05-13 2022-03-31 13F AMKOR TECHNOLOGY COM 031652100 15,334,586 -81,786 -0.53 333,084 -12.84 0.1026
2022-02-09 2021-12-31 13F AMKOR TECHNOLOGY COM 031652100 15,416,372 -512,646 -3.22 382,166 -3.84 0.1155
2021-11-12 2021-09-30 13F AMKOR TECHNOLOGY COM 031652100 15,929,018 -284,155 -1.75 397,436 3.56 0.1280
2021-08-12 2021-06-30 13F AMKOR TECHNOLOGY COM 031652100 16,213,173 -115,289 -0.71 383,769 -1.08 0.1215
2021-05-14 2021-03-31 13F AMKOR TECHNOLOGY COM 031652100 16,328,462 -394,483 -2.36 387,948 53.84 0.1283
2021-03-08 2020-12-31 13F/A-2 AMKOR TECHNOLOGY COM 031652100 16,722,945 -541,893 -3.14 252,184 30.42 0.0911
2021-02-11 2020-12-31 13F AMKOR TECHNOLOGY COM 031652100 16,722,945 -541,893 252,184 91,075.4565
2020-11-12 2020-09-30 13F AMKOR TECHNOLOGY COM 031652100 17,264,838 -342,187 -1.94 193,366 -10.78 0.0820
2020-08-13 2020-06-30 13F AMKOR TECHNOLOGY COM 031652100 17,607,025 -434,073 -2.41 216,733 54.20 0.0953
2020-05-14 2020-03-31 13F AMKOR TECHNOLOGY COM 031652100 18,041,098 -11,363 -0.06 140,549 -40.11 0.0732
2020-02-14 2019-12-31 13F AMKOR TECHNOLOGY COM 031652100 18,052,461 -289,656 -1.58 234,688 40.61 0.0855
2019-11-12 2019-09-30 13F AMKOR TECHNOLOGY COM 031652100 18,342,117 32,071 0.18 166,910 22.20 0.0649
2019-08-13 2019-06-30 13F AMKOR TECHNOLOGY COM 031652100 18,310,046 401,617 2.24 136,592 -10.69 0.0530
2019-08-12 2019-03-31 13F/A-2 AMKOR TECHNOLOGY COM 031652100 17,908,429 485,676 2.79 152,938 33.81 0.0609
2019-05-10 2019-03-31 13F AMKOR TECHNOLOGY COM 031652100 17,908,429 485,676 152,938
2019-02-26 2018-12-31 13F/A-1 AMKOR TECHNOLOGY COM 031652100 17,422,753 744,342 4.46 114,293 -7.27 0.0518
2019-02-13 2018-12-31 13F AMKOR TECHNOLOGY COM 031652100 17,422,753 744,342 114,293
2018-11-13 2018-09-30 13F AMKOR TECHNOLOGY COM 031652100 16,678,411 689,162 4.31 123,254 -10.26 0.0469
2018-08-10 2018-06-30 13F AMKOR TECHNOLOGY COM 031652100 15,989,249 539,780 3.49 137,348 -12.24 0.0548
2018-05-11 2018-03-31 13F AMKOR TECHNOLOGY COM 031652100 15,449,469 428,382 2.85 156,503 3.67 0.0652
2018-02-12 2017-12-31 13F AMKOR TECHNOLOGY COM 031652100 15,021,087 373,150 2.55 150,964 -2.31 0.0626
2017-11-13 2017-09-30 13F AMKOR TECHNOLOGY COM 031652100 14,647,937 678,213 4.85 154,536 13.23 0.0675
2017-08-11 2017-06-30 13F AMKOR TECHNOLOGY COM 031652100 13,969,724 991,891 7.64 136,485 -9.26 0.0630
2017-05-12 2017-03-31 13F AMKOR TECHNOLOGY COM 031652100 12,977,833 1,641,388 14.48 150,410 25.76 0.0719
2017-02-09 2016-12-31 13F AMKOR TECHNOLOGY COM 031652100 11,336,445 835,877 7.96 119,602 17.18 0.0597
2016-11-10 2016-09-30 13F AMKOR TECHNOLOGY COM 031652100 10,500,568 1,042,303 11.02 102,064 87.67 0.0552
2016-08-09 2016-06-30 13F AMKOR TECHNOLOGY COM 031652100 9,458,265 1,078,260 12.87 54,384 10.18 0.0313
2016-05-13 2016-03-31 13F AMKOR TECHNOLOGY COM 031652100 8,380,005 1,167,393 16.19 49,357 12.55 0.0295
2016-02-10 2015-12-31 13F AMKOR TECHNOLOGY COM 031652100 7,212,612 288,176 4.16 43,854 41.06 0.0273
2015-11-13 2015-09-30 13F AMKOR TECHNOLOGY COM 031652100 6,924,436 85,059 1.24 31,090 -23.98 0.0204
2015-08-14 2015-06-30 13F AMKOR TECHNOLOGY COM 031652100 6,839,377 1,258,170 22.54 40,899 -17.06 0.0250
2015-05-14 2015-03-31 13F AMKOR TECHNOLOGY COM 031652100 5,581,207 -276,744 -4.72 49,310 18.56 0.0311
2015-02-06 2014-12-31 13F AMKOR TECHNOLOGY COM 031652100 5,857,951 470,741 8.74 41,592 -8.20 0.0273
2014-11-13 2014-09-30 13F AMKOR TECHNOLOGY COM 031652100 5,387,210 1,109,485 25.94 45,309 -5.26 0.0321
2014-08-08 2014-06-30 13F AMKOR TECHNOLOGY COM 031652100 4,277,725 -35,581 -0.82 47,823 61.63 0.0332
2014-05-14 2014-03-31 13F AMKOR TECHNOLOGY COM 031652100 4,313,306 36,547 0.85 29,588 12.86 0.0221
2014-02-12 2013-12-31 13F AMKOR TECHNOLOGY COM 031652100 4,276,759 102,292 2.45 26,216 46.39 0.0204
2013-11-13 2013-09-30 13F AMKOR TECHNOLOGY COM 031652100 4,174,467 -42,028 -1.00 17,908 0.88 0.0155
2013-08-15 2013-06-30 13F AMKOR TECHNOLOGY COM 031652100 4,216,495 4,216,495 17,751 0.0167
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.