Who owns ASE Technology (ASX)?
35 holders named in SEC filings declare between 30.1% and 30.7% of ASE Technology's shares outstanding, as of Sep 22, 2026. The largest are Chien Shen Chang (21.5%), Hung Pen Chang (2.9%) and BlackRock (1.2%); the five largest hold 26.4% together. Another 459 institutions hold small positions worth 1.4%. At least 67.9% of the shares appear in no ownership filing: investors who do not have to report, mostly individuals. From Mar 31, 2026 to Jun 30, 2026, institutions that filed both quarters bought 1.3% and sold 1.4% of the shares, a net sale of 0.17%; 146 opened a position, 143 added, 137 reduced and 34 sold out. Biggest buyers: BlackRock (+4.1M shares) and Man Group plc (+3.5M shares). Biggest sellers: LAZARD ASSET MANAGEMENT LLC (-5.6M) and Jane Street (-3.1M). Directors and officers, from their latest Form 4: Chien Shen Chang (21.5%), Hung Pen Chang (2.9%) and Chi-Wen Tsai (0.35%). Over time, 479 managers declared ASE Technology in their 13F for Q2 2026, against 117 for Q4 2019: together at most 6.9% of the shares outstanding, against 4.9%.
| Holder | Filing | Share of capital | As of | Holding since (13F) |
|---|---|---|---|---|
| Chien Shen Chang | Form 4 | 21.5% | Apr 9, 2026 | — |
| Hung Pen Chang | Form 4 | 2.9% | Sep 22, 2026 | — |
| BlackRock | 13F | 1.2% | Jun 30, 2026 | Q4 2019 or earlier |
| Bank of America | 13F | 0.42% | Jun 30, 2026 | Q4 2019 or earlier |
| Goldman Sachs | 13F | 0.37% | Jun 30, 2026 | Q4 2021 |
| LAZARD ASSET MANAGEMENT LLC | 13F | 0.36% | Jun 30, 2026 | Q4 2019 or earlier |
| Chi-Wen Tsai | Form 4 | 0.35% | Sep 7, 2026 | — |
| UBS | 13F | 0.35% | Jun 30, 2026 | Q4 2019 or earlier |
| Morgan Stanley | 13F | 0.26% | Jun 30, 2026 | Q4 2019 or earlier |
| Rafferty Asset Management, LLC | 13F | 0.25% | Jun 30, 2026 | Q4 2021 |
| American Century Companies, Inc. | 13F | 0.24% | Jun 30, 2026 | Q4 2019 or earlier |
| JPMorgan | 13F | 0.24% | Jun 30, 2026 | Q4 2019 or earlier |
| ACADIAN ASSET MANAGEMENT LLC | 13F | 0.22% | Jun 30, 2026 | Q2 2020 |
| Fisher Asset Management, LLC | 13F | 0.20% | Jun 30, 2026 | Q4 2019 or earlier |
| CITIGROUP INC | 13F | 0.19% | Jun 30, 2026 | Q4 2019 or earlier |
| Tien-Yue Wu | Form 4 | 0.19% | Sep 7, 2026 | — |
| Man Group plc | 13F | 0.17% | Jun 30, 2026 | Q1 2026 |
| Barclays | 13F | 0.16% | Jun 30, 2026 | Q2 2021 |
| Hung-Szu Tung | Form 4 | 0.10% | Sep 7, 2026 | — |
| Raymond Lo | Form 4 | 0.10% | Sep 7, 2026 | — |
| Cullen Capital Management, LLC | 13F | 0.09% | Jun 30, 2026 | Q4 2019 or earlier |
| Creative Planning | 13F | 0.09% | Jun 30, 2026 | Q1 2024 |
| DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main | 13F | 0.08% | Jun 30, 2026 | Q1 2026 |
| Dimensional | 13F | 0.07% | Jun 30, 2026 | Q4 2019 or earlier |
| EARNEST PARTNERS LLC | 13F | 0.06% | Jun 30, 2026 | Q4 2019 or earlier |
ASE Technology institutional ownership over time
| Quarter | 13F managers | Share of the company (upper bound) | Value declared | Held by stock pickers |
|---|---|---|---|---|
| Q4 2019 | 117 | 4.9% | $595.1M | 88.7% |
| Q4 2020 | 147 | 4.2% | $528.3M | 89.2% |
| Q4 2021 | 196 | 5.9% | $1.0B | 76.3% |
| Q4 2022 | 220 | 7.2% | $988.5M | 73.4% |
| Q4 2023 | 260 | 6.8% | $1.4B | 70.7% |
| Q4 2024 | 284 | 7.6% | $1.7B | 63.8% |
| Q4 2025 | 313 | 7.2% | $2.6B | 59.2% |
| Q2 2026 | 479 | 6.9% | $6.9B | 55.1% |
From SEC Form 13F, every quarter since the end of 2019, read like the current quarter: entities of a house summed, a value contradicting its share count set aside. The share of the company is an upper bound — two managers can declare the same shares — over the shares outstanding at that date.