Who owns Allegro MicroSystems (ALGM)?
76 holders named in SEC filings declare between 52.4% and 77.6% of Allegro MicroSystems' shares outstanding, as of Aug 5, 2026. The largest are Fidelity (FMR) (13.7%), Vanguard (7.6%) and BlackRock (7.5%); the five largest hold 42.9% together. Another 297 institutions hold small positions worth 2.4%. At least 20.0% 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 11.4% and sold 6.8% of the shares, a net purchase of 4.6%; 93 opened a position, 110 added, 102 reduced and 41 sold out. Biggest buyers: Invesco (+4.9M shares) and JPMorgan (+4.1M shares). Biggest sellers: Fidelity (FMR) (-1.8M) and NOMURA ASSET MANAGEMENT INTERNATIONAL INC. (-921,138). Schedule 13D/G filings since Mar 31, 2026: BlackRock, Inc. crossed 5% (6.9%) on Jun 30, 2026, FMR LLC cut its stake to 13.7% on Jun 30, 2026, Invesco Ltd. crossed 5% (7.3%) on Jun 30, 2026 and JPMORGAN CHASE & CO. raised its stake to 6.8% on Jun 30, 2026. Directors and officers, from their latest Form 4: Michael Doogue (0.29%). Over time, 365 managers declared Allegro MicroSystems in their 13F for Q2 2026, against 92 for Q4 2020: together at most 79.6% of the shares outstanding, against 39.3%.
| Holder | Filing | Share of capital | As of | Holding since (13F) |
|---|---|---|---|---|
| Fidelity (FMR) | 13F | 13.7% | Jun 30, 2026 | Q4 2020 |
| Vanguard | 13F | 7.6% | Jun 30, 2026 | Q4 2020 |
| BlackRock | 13F | 7.5% | Jun 30, 2026 | Q4 2020 |
| Invesco | 13F | 7.3% | Jun 30, 2026 | Q4 2020 |
| JPMorgan | 13F | 6.8% | Jun 30, 2026 | Q4 2020 |
| Capital Group | 13F | 6.4% | Jun 30, 2026 | Q3 2024 |
| State Street | 13F | 3.0% | Jun 30, 2026 | Q4 2020 |
| T. Rowe Price | 13F | 2.3% | Jun 30, 2026 | Q4 2022 |
| Clearbridge Investments, LLC | 13F | 1.6% | Jun 30, 2026 | Q4 2020 |
| Geode Capital | 13F | 1.4% | Jun 30, 2026 | Q4 2020 |
| Dimensional | 13F | 1.1% | Jun 30, 2026 | Q3 2021 |
| Morgan Stanley | 13F | 0.97% | Jun 30, 2026 | Q4 2020 |
| LOOMIS SAYLES & CO L P | 13F | 0.87% | Jun 30, 2026 | Q3 2024 |
| Goldman Sachs | 13F | 0.84% | Jun 30, 2026 | Q4 2020 |
| PRINCIPAL FINANCIAL GROUP INC | 13F | 0.80% | Jun 30, 2026 | Q4 2020 |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ | 13F | 0.77% | Jun 30, 2026 | Q1 2023 |
| Charles Schwab | 13F | 0.73% | Jun 30, 2026 | Q4 2020 |
| Norges Bank | 13F | 0.69% | Jun 30, 2026 | Q4 2020 |
| ALLIANCEBERNSTEIN L.P. | 13F | 0.64% | Jun 30, 2026 | Q4 2020 |
| Northern Trust | 13F | 0.63% | Jun 30, 2026 | Q4 2020 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. | 13F | 0.62% | Jun 30, 2026 | Q4 2025 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | 13F | 0.60% | Jun 30, 2026 | Q4 2020 |
| UBS | 13F | 0.59% | Jun 30, 2026 | Q4 2020 |
| VOYA INVESTMENT MANAGEMENT LLC | 13F | 0.52% | Jun 30, 2026 | Q1 2021 |
| RAYMOND JAMES FINANCIAL INC | 13F | 0.50% | Jun 30, 2026 | Q4 2024 |
Allegro MicroSystems institutional ownership over time
| Quarter | 13F managers | Share of the company (upper bound) | Value declared | Held by stock pickers |
|---|---|---|---|---|
| Q4 2020 | 92 | 39.3% | $2.0B | 90.3% |
| Q4 2021 | 161 | 46.3% | $3.2B | 77.1% |
| Q4 2022 | 216 | 50.4% | $2.9B | 73.0% |
| Q4 2023 | 279 | 50.0% | $2.9B | 69.8% |
| Q4 2024 | 249 | 77.2% | $3.1B | 66.0% |
| Q4 2025 | 288 | 73.8% | $3.6B | 61.5% |
| Q2 2026 | 365 | 79.6% | $10.3B | 58.1% |
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.