Who owns Alpha & Omega Semiconductor (AOSL)?
90 holders named in SEC filings declare between 77.9% and 93.1% of Alpha & Omega Semiconductor's shares outstanding, as of Aug 24, 2026. The largest are Mike F. Chang (14.1%), BlackRock (14.1%) and Vanguard (7.8%); the five largest hold 48.2% together. Another 134 institutions hold small positions worth 1.5%. At least 5.4% 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 13.7% and sold 11.2% of the shares, a net purchase of 2.4%; 60 opened a position, 56 added, 63 reduced and 23 sold out. Biggest buyers: State Street (+945,898 shares) and Two Sigma (+398,565 shares). Biggest sellers: Wellington (-281,898) and JPMorgan (-234,466). Schedule 13D/G filings since Mar 31, 2026: Dimensional Fund Advisors LP fell below 5% (4.4% still declared) on Jun 30, 2026, Mike F. Chang raised its stake to 13.9% on Jun 30, 2026 and STATE STREET CORPORATION crossed 5% (7.8%) on Jun 30, 2026. Directors and officers, from their latest Form 4: Mike F. Chang (14.1%), Stephen Chunping Chang (2.4%) and Yifan Liang (0.89%). Over time, 207 managers declared Alpha & Omega Semiconductor in their 13F for Q2 2026, against 79 for Q4 2019: together at most 76.3% of the shares outstanding, against 60.5%.
| Holder | Filing | Share of capital | As of | Holding since (13F) |
|---|---|---|---|---|
| Mike F. Chang | Form 4 | 14.1% | Aug 24, 2026 | — |
| BlackRock | 13F | 14.1% | Jun 30, 2026 | Q4 2019 or earlier |
| Vanguard | 13F | 7.8% | Jun 30, 2026 | Q4 2019 or earlier |
| State Street | 13F | 7.8% | Jun 30, 2026 | Q4 2019 or earlier |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE | 13F | 4.5% | Jun 30, 2026 | Q4 2019 or earlier |
| Dimensional | 13F | 4.4% | Jun 30, 2026 | Q4 2019 or earlier |
| Two Sigma | 13F | 3.1% | Jun 30, 2026 | Q3 2020 |
| Fidelity (FMR) | 13F | 2.6% | Jun 30, 2026 | Q4 2019 or earlier |
| Stephen Chunping Chang | Form 4 | 2.4% | Aug 24, 2026 | — |
| Geode Capital | 13F | 2.2% | Jun 30, 2026 | Q4 2019 or earlier |
| Connor, Clark & Lunn Investment Management Ltd. | 13F | 2.1% | Jun 30, 2026 | Q2 2023 |
| WEBER CAPITAL MANAGEMENT LLC /ADV | 13F | 1.8% | Jun 30, 2026 | Q4 2025 |
| Wellington | 13F | 1.4% | Jun 30, 2026 | Q2 2023 |
| Charles Schwab | 13F | 1.3% | Jun 30, 2026 | Q4 2019 or earlier |
| ACADIAN ASSET MANAGEMENT LLC | 13F | 1.1% | Jun 30, 2026 | Q2 2025 |
| ROYCE & ASSOCIATES LP | 13F | 1.0% | Jun 30, 2026 | Q4 2019 or earlier |
| D. E. Shaw | 13F | 0.94% | Jun 30, 2026 | Q4 2025 |
| Goldman Sachs | 13F | 0.92% | Jun 30, 2026 | Q4 2019 or earlier |
| Yifan Liang | Form 4 | 0.89% | Apr 28, 2026 | — |
| Millennium | 13F | 0.88% | Jun 30, 2026 | Q2 2025 |
| Northern Trust | 13F | 0.86% | Jun 30, 2026 | Q4 2019 or earlier |
| Jane Street | 13F | 0.77% | Jun 30, 2026 | Q2 2026 |
| Morgan Stanley | 13F | 0.72% | Jun 30, 2026 | Q4 2019 or earlier |
| Invesco | 13F | 0.69% | Jun 30, 2026 | Q4 2019 or earlier |
| Apis Capital Advisors, LLC | 13F | 0.68% | Jun 30, 2026 | Q2 2026 |
Alpha & Omega Semiconductor institutional ownership over time
| Quarter | 13F managers | Share of the company (upper bound) | Value declared | Held by stock pickers |
|---|---|---|---|---|
| Q4 2019 | 79 | 60.5% | $208.5M | 74.6% |
| Q4 2020 | 97 | 59.9% | $361.1M | 74.8% |
| Q4 2021 | 171 | 56.8% | $904.3M | 61.0% |
| Q4 2022 | 159 | 64.9% | $508.2M | 50.7% |
| Q4 2023 | 140 | 65.2% | $472.5M | 50.1% |
| Q4 2024 | 171 | 70.7% | $760.1M | 52.5% |
| Q4 2025 | 164 | 74.6% | $444.1M | 52.0% |
| Q2 2026 | 207 | 76.3% | $1.1B | 48.6% |
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.