Who owns MACOM (MTSI)?
126 holders named in SEC filings declare between 78.5% and 98.4% of MACOM's shares outstanding, as of Jun 30, 2026. The largest are Fidelity (FMR) (13.8%), BlackRock (12.5%) and Vanguard (9.4%); the five largest hold 47.0% together. Another 530 institutions hold small positions worth 3.8%. From Mar 31, 2026 to Jun 30, 2026, institutions that filed both quarters bought 11.3% and sold 13.8% of the shares, a net sale of 2.6%; 175 opened a position, 197 added, 186 reduced and 38 sold out. Biggest buyers: BlackRock (+946,616 shares) and Qube Research & Technologies Ltd (+790,678 shares). Biggest sellers: T. Rowe Price (-1.6M) and Invesco (-1.5M). Schedule 13D/G filings since Mar 31, 2026: BlackRock, Inc. raised its stake to 10.4% on Jun 30, 2026 and Susan M. Ocampo cut its stake to 6.4% on Jun 30, 2026. Over time, 643 managers declared MACOM in their 13F for Q2 2026, against 149 for Q4 2019: together at most 95.8% of the shares outstanding, against 72.6%.
| Holder | Filing | Share of capital | As of | Holding since (13F) |
|---|---|---|---|---|
| Fidelity (FMR) | 13F | 13.8% | Jun 30, 2026 | Q3 2020 |
| BlackRock | 13F | 12.5% | Jun 30, 2026 | Q4 2019 or earlier |
| Vanguard | 13F | 9.4% | Jun 30, 2026 | Q4 2019 or earlier |
| Susan M. Ocampo | 13G | 6.4% | Jun 30, 2026 | — |
| T. Rowe Price | 13F | 5.0% | Jun 30, 2026 | Q4 2019 or earlier |
| State Street | 13F | 3.0% | Jun 30, 2026 | Q4 2019 or earlier |
| Invesco | 13F | 2.8% | Jun 30, 2026 | Q4 2019 or earlier |
| JPMorgan | 13F | 2.8% | Jun 30, 2026 | Q4 2019 or earlier |
| Geode Capital | 13F | 1.8% | Jun 30, 2026 | Q4 2019 or earlier |
| Wellington | 13F | 1.6% | Jun 30, 2026 | Q4 2024 |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ | 13F | 1.5% | Jun 30, 2026 | Q4 2024 |
| Capital Group | 13F | 1.4% | Jun 30, 2026 | Q4 2019 or earlier |
| Norges Bank | 13F | 1.3% | Jun 30, 2026 | Q4 2019 or earlier |
| Whale Rock Capital Management LLC | 13F | 1.3% | Jun 30, 2026 | Q4 2025 |
| Neuberger Berman Group LLC | 13F | 1.1% | Jun 30, 2026 | Q4 2019 or earlier |
| Goldman Sachs | 13F | 1.1% | Jun 30, 2026 | Q4 2019 or earlier |
| Franklin Templeton | 13F | 1.0% | Jun 30, 2026 | Q3 2022 |
| Qube Research & Technologies Ltd | 13F | 1.0% | Jun 30, 2026 | Q2 2026 |
| Polar Capital Holdings Plc | 13F | 0.98% | Jun 30, 2026 | Q1 2026 |
| Janus Henderson | 13F | 0.88% | Jun 30, 2026 | Q4 2022 |
| Charles Schwab | 13F | 0.87% | Jun 30, 2026 | Q4 2019 or earlier |
| Bank of America | 13F | 0.85% | Jun 30, 2026 | Q4 2019 or earlier |
| GW&K Investment Management, LLC | 13F | 0.83% | Jun 30, 2026 | Q4 2019 or earlier |
| Rafferty Asset Management, LLC | 13F | 0.83% | Jun 30, 2026 | Q3 2025 |
| Artisan Partners Limited Partnership | 13F | 0.82% | Jun 30, 2026 | Q3 2022 |
MACOM institutional ownership over time
| Quarter | 13F managers | Share of the company (upper bound) | Value declared | Held by stock pickers |
|---|---|---|---|---|
| Q4 2019 | 149 | 72.6% | $1.3B | 71.0% |
| Q4 2020 | 192 | 71.7% | $2.7B | 67.6% |
| Q4 2021 | 223 | 71.9% | $3.9B | 66.5% |
| Q4 2022 | 260 | 75.4% | $3.4B | 65.4% |
| Q4 2023 | 291 | 81.2% | $5.4B | 62.2% |
| Q4 2024 | 376 | 86.1% | $8.1B | 64.3% |
| Q4 2025 | 455 | 95.9% | $12.3B | 60.1% |
| Q2 2026 | 643 | 95.8% | $27.8B | 58.8% |
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.