Comparable stake leader
James J. Kim
SEC ownership of AMKOR TECHNOLOGY, INC.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001047127.
Disclosed value leader
John T. Kim
Comparable rows
2/50
Latest evidence
22 Sep 2026
- Public ticker
- AMKR on Nasdaq
- Parsed ownership sources
-
13D/G, 3/4/5, and 13F
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
James J. Kim
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
2 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
James J. Kim
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
22 Sep 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001047127
- Issuer location
- Tempe, AZ
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of AMKOR TECHNOLOGY, INC. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
James J. Kim
Disclosed value leader
John T. Kim
Comparable rows
2/50
Latest evidence
22 Sep 2026
13D/G
3/4/5
13F
Lead comparable stake: 30%
48 rows are not safely comparable across share classes.
13D/G row: James J. Kim
Showing 1-8 of 50 holder rows.
Quick read
James J. Kim leads the comparable SEC ownership view at 30%.
2 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens James J. Kim's linked filing trail.
Comparable ownership
Top 2
James J. Kim
30%
DIMENSIONAL FUND ADVISORS LP
4.4%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| James J. Kim |
13D/G
3/4/5
John T. Kim · Member of 10% owner group (5), 10%+ Owner
|
30%
Reported 13D/G
· 01 May 2026
|
$4,366,654,410
75,339,103 shares
|
$0 | 01 May 2026 |
| DIMENSIONAL FUND ADVISORS LP |
13F
13D/G
Company
|
4.4%
Reported 13D/G
· 31 Mar 2026
|
$695,285,204
8,064,191 shares
|
— | 30 Jun 2026 |
| John T. Kim |
3/4/5
Member of 10% owner group (6), 10%+ Owner
|
—
denominator unverified
|
$4,398,838,899
86,274,619 shares
|
-$484,900,000 | 12 Feb 2026 |
| Susan Y. Kim |
3/4/5
Director, Member of 10% owner group (5), 10%+ Owner
|
—
mixed-class rows
|
$3,634,193,891
42,147,499 shares
mixed-class rows
|
— | 22 Sep 2026 |
| 915 Investments, LP |
3/4/5
Member of 10% owner group (2)
|
—
denominator unverified
|
$1,435,060,580
29,594,980 shares
|
-$484,900,000 | 12 Feb 2026 |
| Agnes C. Kim |
3/4/5
Member of 10% owner group (4)
|
—
denominator unverified
|
$964,685,621
11,187,355 shares
|
— | 20 Jul 2026 |
| Kim Capital Partners - KCP, LLC |
3/4/5
Member of 10% owner group (3)
|
—
denominator unverified
|
$534,741,376
16,710,668 shares
|
— | 14 Nov 2023 |
| David D. Kim |
3/4/5
Member of 10% owner group (5)
|
—
denominator unverified
|
$141,980,797
6,496,738 shares
|
— | 01 Aug 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$992,174,759.
Buys
$0
Insiders: 0
Sells
$992,174,759
Insiders: 12
Net
-$992,174,759
Shares: -20,400,661
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 20,400,661
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 68,000 | $0 | $3,749,620 | -$3,749,620 |
| 3-6 | 0 | 123,221 | $0 | $9,178,347 | -$9,178,347 |
| 6-9 | 0 | 20,078,440 | $0 | $973,632,432 | -$973,632,432 |
| 9-12 | 0 | 131,000 | $0 | $5,614,360 | -$5,614,360 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 55 reporting-owner rows connected to AMKOR TECHNOLOGY, INC.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
55
Largest Forms 3/4/5 holder
John T. Kim
Net 12M change
-$992.17M
Full value: -$992,174,759 · USD · 12-month changeLatest report
13 Oct 2026
Recent insider transactions for AMKOR TECHNOLOGY, INC.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Megan Faust | AMKR | Common Stock | Sale | -0.75% | -$46,920 | $46.92 | -1,000 | 133,105 | 13 Oct 2026 | Direct |
| Douglas A. Alexander | AMKR | Common Stock | Sale | -14.7% | -$275,000 | $55.00 | -5,000 | 29,109 | 02 Oct 2026 | Direct |
| Douglas A. Alexander | AMKR | Common Stock | Options Exercise | 17.2% | 5,000 | 34,109 | 02 Oct 2026 | Direct | ||
| Douglas A. Alexander | AMKR | Director Stock Option (Right-to-Buy) | Options Exercise | -34.1% | -5,000 | 9,657 | 02 Oct 2026 | Direct | ||
| Susan Y. Kim | AMKR | Restricted Stock Units | Award | 0.15% | 4 | 2,620 | 22 Sep 2026 | Direct | ||
| David N. Watson | AMKR | Restricted Stock Units | Award | 0.15% | 4 | 2,620 | 22 Sep 2026 | Direct | ||
| Gil C. Tily | AMKR | Restricted Stock Units | Award | 0.15% | 4 | 2,620 | 22 Sep 2026 | Direct | ||
| Guillaume Marie Jean Rutten | AMKR | Restricted Stock Units | Award | 0.15% | 4 | 2,620 | 22 Sep 2026 | Direct | ||
| Robert R. Morse | AMKR | Restricted Stock Units | Award | 0.32% | 31.95 | 9,917 | 22 Sep 2026 | Direct | ||
| MaryFrances McCourt | AMKR | Restricted Stock Units | Award | 0.19% | 16.97 | 8,917 | 22 Sep 2026 | Direct | ||
| Daniel Jl Liao | AMKR | Restricted Stock Units | Award | 0.19% | 18.97 | 9,917 | 22 Sep 2026 | Direct | ||
| Winston J. Churchill | AMKR | Restricted Stock Units | Award | 0.15% | 4 | 2,620 | 22 Sep 2026 | Direct | ||
| Roger A. Carolin | AMKR | Restricted Stock Units | Award | 0.32% | 31.95 | 9,917 | 22 Sep 2026 | Direct | ||
| Douglas A. Alexander | AMKR | Restricted Stock Units | Award | 0.46% | 45.27 | 9,917 | 22 Sep 2026 | Direct | ||
| Megan Faust | AMKR | Common Stock | Sale | -0.74% | -$49,050 | $49.05 | -1,000 | 134,105 | 08 Sep 2026 | Direct |
| Mark N. Rogers | AMKR | Common Stock | Sale | -11.4% | -$298,900 | $59.78 | -5,000 | 38,904 | 17 Aug 2026 | Direct |
| Mark N. Rogers | AMKR | Common Stock | Options Exercise | 12.8% | 5,000 | 43,904 | 17 Aug 2026 | Direct | ||
| Mark N. Rogers | AMKR | Employee Stock Option (Right-to-Buy) | Options Exercise | -6.67% | -5,000 | 70,000 | 17 Aug 2026 | Direct | ||
| Megan Faust | AMKR | Common Stock | Sale | -0.73% | -$54,450 | $54.45 | -1,000 | 135,105 | 11 Aug 2026 | Direct |
| Douglas A. Alexander | AMKR | Common Stock | Sale | -14.7% | -$279,050 | $55.81 | -5,000 | 29,109 | 07 Aug 2026 | Direct |
| Douglas A. Alexander | AMKR | Common Stock | Options Exercise | 17.2% | 5,000 | 34,109 | 07 Aug 2026 | Direct | ||
| Douglas A. Alexander | AMKR | Director Stock Option (Right-to-Buy) | Options Exercise | -25.4% | -5,000 | 14,657 | 07 Aug 2026 | Direct | ||
| Guillaume Marie Jean Rutten | AMKR | Common Stock | Sale | -5.14% | -$1,362,500 | $54.50 | -25,000 | 461,732 | 06 Aug 2026 | Direct |
| Guillaume Marie Jean Rutten | AMKR | Common Stock | Sale | -4.89% | -$1,383,750 | $55.35 | -25,000 | 486,732 | 05 Aug 2026 | Direct |
| Winston J. Churchill | AMKR | Common Stock | Gift | -0.35% | -100 | 28,681 | 30 Jul 2026 | Direct | ||
| Kevin K. Engel | AMKR | Common Stock | Sale | -25% | -$151,387 | $47.00 | -3,221 | 9,666 | 30 Jul 2026 | Direct |
| Agnes C. Kim | AMKR | Common Stock | Options Exercise | 4.19% | 450,000 | 11,187,355 | 20 Jul 2026 | By Spouse | ||
| James J. Kim | AMKR | Common Stock | Options Exercise | 730% | 450,000 | 511,645 | 20 Jul 2026 | Direct | ||
| James J. Kim | AMKR | Employee Stock Option (Right-to-Buy) | Options Exercise | -100% | -450,000 | 0 | 20 Jul 2026 | Direct | ||
| Mark N. Rogers | AMKR | Common Stock | Sale | -11.4% | -$325,600 | $65.12 | -5,000 | 38,904 | 16 Jul 2026 | Direct |
| Mark N. Rogers | AMKR | Common Stock | Options Exercise | 12.8% | 5,000 | 43,904 | 16 Jul 2026 | Direct | ||
| Mark N. Rogers | AMKR | Employee Stock Option (Right-to-Buy) | Options Exercise | -6.25% | -5,000 | 75,000 | 16 Jul 2026 | Direct | ||
| Megan Faust | AMKR | Common Stock | Sale | -0.73% | -$69,910 | $69.91 | -1,000 | 136,105 | 14 Jul 2026 | Direct |
| Kevin K. Engel | AMKR | Common Stock | Tax liability | -22.4% | -3,725 | 12,887 | 30 Jun 2026 | Direct | ||
| Kevin K. Engel | AMKR | Common Stock | Options Exercise | 109.8% | 8,692 | 16,612 | 30 Jun 2026 | Direct | ||
| Kevin K. Engel | AMKR | Restricted Stock Units | Options Exercise | -100% | -8,692 | 0 | 30 Jun 2026 | Direct | ||
| Megan Faust | AMKR | Common Stock | Tax liability | -2.65% | -3,725 | 137,105 | 30 Jun 2026 | Direct | ||
| Megan Faust | AMKR | Common Stock | Options Exercise | 6.58% | 8,692 | 140,830 | 30 Jun 2026 | Direct | ||
| Megan Faust | AMKR | Restricted Stock Units | Options Exercise | -100% | -8,692 | 0 | 30 Jun 2026 | Direct | ||
| Guillaume Marie Jean Rutten | AMKR | Common Stock | Options Exercise | 1.73% | 8,692 | 511,732 | 30 Jun 2026 | Direct | ||
| Guillaume Marie Jean Rutten | AMKR | Restricted Stock Units | Options Exercise | -100% | -8,692 | 0 | 30 Jun 2026 | Direct | ||
| Susan Y. Kim | AMKR | Restricted Stock Units | Award | 0.1% | 2.52 | 2,616 | 23 Jun 2026 | Direct | ||
| David N. Watson | AMKR | Restricted Stock Units | Award | 0.1% | 2.52 | 2,616 | 23 Jun 2026 | Direct | ||
| Gil C. Tily | AMKR | Restricted Stock Units | Award | 0.1% | 2.52 | 2,616 | 23 Jun 2026 | Direct | ||
| Guillaume Marie Jean Rutten | AMKR | Restricted Stock Units | Award | 0.1% | 2.52 | 2,616 | 23 Jun 2026 | Direct | ||
| Robert R. Morse | AMKR | Restricted Stock Units | Award | 0.2% | 20.11 | 9,902 | 23 Jun 2026 | Direct | ||
| MaryFrances McCourt | AMKR | Restricted Stock Units | Award | 0.12% | 10.68 | 8,904 | 23 Jun 2026 | Direct | ||
| Daniel Jl Liao | AMKR | Restricted Stock Units | Award | 0.12% | 11.94 | 9,902 | 23 Jun 2026 | Direct | ||
| Winston J. Churchill | AMKR | Restricted Stock Units | Award | 0.1% | 2.52 | 2,616 | 23 Jun 2026 | Direct | ||
| Roger A. Carolin | AMKR | Restricted Stock Units | Award | 0.2% | 20.11 | 9,902 | 23 Jun 2026 | Direct |
* marks a reported price that did not pass the local price check.