Who owns Vicor (VICR)?
84 holders named in SEC filings declare between 58.7% and 64.8% of Vicor's shares outstanding, as of Oct 1, 2026. The largest are Patrizio Vinciarelli (18.4%), T. Rowe Price (9.5%) and Vanguard (5.5%); the five largest hold 41.8% together. Another 428 institutions hold small positions worth 3.3%. At least 31.9% 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 8.0% and sold 6.0% of the shares, a net purchase of 2.1%; 177 opened a position, 151 added, 127 reduced and 39 sold out. Biggest buyers: T. Rowe Price (+613,777 shares) and Driehaus Capital Management LLC (+307,044 shares). Biggest sellers: BlackRock (-423,446) and Millennium (-159,087). Schedule 13D/G filings since Mar 31, 2026: JPMORGAN CHASE & CO. fell below 5% (3.0% still declared) on Aug 31, 2026, T. Rowe Price Associates, Inc. raised its stake to 9.5% on Aug 31, 2026 and BlackRock, Inc. cut its stake to 4.9% on Jun 30, 2026. Directors and officers, from their latest Form 4: Patrizio Vinciarelli (18.4%) and Estia J. Eichten (0.23%). Over time, 500 managers declared Vicor in their 13F for Q2 2026, against 135 for Q4 2019: together at most 45.9% of the shares outstanding, against 28.6%.
| Holder | Filing | Share of capital | As of | Holding since (13F) |
|---|---|---|---|---|
| Patrizio Vinciarelli | Form 4 | 18.4% | Oct 1, 2026 | — |
| T. Rowe Price | 13G | 9.5% | Aug 31, 2026 | — |
| Vanguard | 13F | 5.5% | Jun 30, 2026 | Q4 2019 or earlier |
| BlackRock | 13F | 5.3% | Jun 30, 2026 | Q4 2019 or earlier |
| JPMorgan | 13G | 3.0% | Aug 31, 2026 | — |
| State Street | 13F | 1.6% | Jun 30, 2026 | Q4 2019 or earlier |
| Geode Capital | 13F | 1.3% | Jun 30, 2026 | Q4 2019 or earlier |
| Jane Street | 13F | 1.2% | Jun 30, 2026 | Q1 2026 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE | 13F | 1.2% | Jun 30, 2026 | Q4 2019 or earlier |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | 13F | 1.2% | Jun 30, 2026 | Q4 2024 |
| NEEDHAM INVESTMENT MANAGEMENT LLC | 13F | 1.1% | Jun 30, 2026 | Q4 2019 or earlier |
| Driehaus Capital Management LLC | 13F | 1.1% | Jun 30, 2026 | Q1 2026 |
| Dimensional | 13F | 1.1% | Jun 30, 2026 | Q4 2019 or earlier |
| AQR | 13F | 0.97% | Jun 30, 2026 | Q1 2020 |
| Goldman Sachs | 13F | 0.81% | Jun 30, 2026 | Q4 2019 or earlier |
| Invesco | 13F | 0.53% | Jun 30, 2026 | Q4 2019 or earlier |
| Morgan Stanley | 13F | 0.50% | Jun 30, 2026 | Q4 2019 or earlier |
| UBS | 13F | 0.45% | Jun 30, 2026 | Q4 2019 or earlier |
| ACADIAN ASSET MANAGEMENT LLC | 13F | 0.44% | Jun 30, 2026 | Q2 2024 |
| Northern Trust | 13F | 0.42% | Jun 30, 2026 | Q4 2019 or earlier |
| Charles Schwab | 13F | 0.34% | Jun 30, 2026 | Q4 2019 or earlier |
| FIRST TRUST ADVISORS LP | 13F | 0.34% | Jun 30, 2026 | Q4 2019 or earlier |
| COLRAIN CAPITAL LLC | 13F | 0.33% | Jun 30, 2026 | Q4 2024 |
| AWM Investment Company, Inc. | 13F | 0.32% | Jun 30, 2026 | Q2 2020 |
| BNY | 13F | 0.30% | Jun 30, 2026 | Q4 2019 or earlier |
Vicor institutional ownership over time
| Quarter | 13F managers | Share of the company (upper bound) | Value declared | Held by stock pickers |
|---|---|---|---|---|
| Q4 2019 | 135 | 28.6% | $598.4M | 48.6% |
| Q4 2020 | 189 | 35.8% | $1.4B | 44.5% |
| Q4 2021 | 235 | 38.7% | $2.2B | 52.3% |
| Q4 2022 | 192 | 40.0% | $965.9M | 55.7% |
| Q4 2023 | 197 | 44.3% | $897.0M | 52.5% |
| Q4 2024 | 195 | 43.4% | $947.4M | 52.6% |
| Q4 2025 | 283 | 45.1% | $2.2B | 54.6% |
| Q2 2026 | 500 | 45.9% | $8.3B | 58.4% |
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.