Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
1,080 institutional managers reported holding MPWR for the quarter ended Mar 31, 2026. Together they hold about 93% of shares outstanding; the top 10 hold 52%. 166 opened new positions; 125 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| Vanguard Group | 6.10M | 12.39% | $6.67B | added +0.9% | ≤2013 |
| BlackRock | 6.07M | 12.33% | $6.64B | added +1.8% | ≤2013 |
| FMR (Fidelity) | 4.40M | 8.94% | $4.81B | added +10.7% | ≤2013 |
| State Street | 2.19M | 4.44% | $2.39B | unchanged | ≤2013 |
| Invesco | 1.49M | 3.02% | $1.62B | added +3.5% | ≤2013 |
| Geode Capital | 1.43M | 2.91% | $1.57B | added +3.6% | ≤2013 |
| T. Rowe Price | 1.26M | 2.56% | $1.38B | trimmed -25.3% | ≤2013 |
| Franklin Resources | 928.7k | 1.89% | $1.01B | trimmed -11.5% | 2016 Q2 |
| UBS | 842.6k | 1.71% | $920.9M | added +11.2% | ≤2013 |
| T. Rowe Price Investment Management, INC. | 721.6k | 1.47% | $788.7M | added +51.5% | 2024 Q4 |
| Morgan Stanley | 656.4k | 1.33% | $717.3M | added +1.1% | ≤2013 |
| First Trust Advisors LP | 591.4k | 1.20% | $646.3M | trimmed -15.7% | ≤2013 |
| Goldman Sachs | 568.1k | 1.15% | $620.8M | trimmed -4.3% | ≤2013 |
| MFS Investment Management | 567.8k | 1.15% | $620.5M | trimmed -0.5% | 2014 Q4 |
| Barclays PLC | 555.8k | 1.13% | $607.4M | trimmed -8.1% | ≤2013 |
| VAN ECK Associates CORP | 524.6k | 1.06% | $573.3M | added +4.4% | 2020 Q4 |
| Northern Trust | 489.1k | 0.99% | $534.6M | added +1.1% | ≤2013 |
| Royal Bank OF Canada | 473.4k | 0.96% | $517.3M | added +168.1% | ≤2013 |
| Voya Investment Management LLC | 393.6k | 0.80% | $430.1M | added +15.8% | ≤2013 |
| Bank OF America CORP /DE/ | 382.2k | 0.78% | $417.7M | trimmed -30.5% | ≤2013 |
| Legal & General Group PLC | 380.1k | 0.77% | $415.4M | added +6.6% | 2014 Q3 |
| Brown Advisory INC | 379.9k | 0.77% | $415.2M | trimmed -24.1% | 2017 Q2 |
| Charles Schwab Investment Management | 376.4k | 0.76% | $411.3M | added +3% | ≤2013 |
| BNP Paribas Financial Markets | 354.0k | 0.72% | $386.9M | trimmed -2.4% | 2014 Q2 |
| Citigroup INC | 340.8k | 0.69% | $372.5M | added +38.8% | ≤2013 |
| Rafferty Asset Management, LLC | 317.5k | 0.65% | $347.0M | trimmed -19.9% | 2017 Q1 |
| BNY Mellon | 289.8k | 0.59% | $316.8M | trimmed -1.8% | ≤2013 |
| Kayne Anderson Rudnick Investment Management LLC | 266.7k | 0.54% | $291.4M | trimmed -9.3% | 2022 Q4 |
| Wellington Management | 250.5k | 0.51% | $273.8M | trimmed -34.9% | ≤2013 |
| Anther Capital LTD (focused) | 233.3k | 0.47% | $255.0M | opened | 2026 Q1 |
| American Century Companies INC | 199.7k | 0.41% | $218.2M | trimmed -1.9% | 2015 Q2 |
| Raymond James Financial INC | 196.1k | 0.40% | $214.3M | trimmed -7.3% | 2015 Q4 |
| DekaBank Deutsche Girozentrale | 190.4k | 0.39% | $208.1M | unchanged | 2016 Q3 |
| SG Americas Securities, LLC | 181.8k | 0.37% | $198.7M | trimmed -30.7% | 2014 Q4 |
| Deutsche Bank AG\ | 181.7k | 0.37% | $198.6M | added +4.2% | 2013 Q3 |
| Principal Financial Group INC | 175.0k | 0.35% | $191.2M | added +4.1% | ≤2013 |
| Mitsubishi UFJ Asset Management CO., LTD. | 163.5k | 0.33% | $178.7M | added +10.2% | 2017 Q2 |
| CalPERS | 159.7k | 0.32% | $174.5M | added +88.2% | ≤2013 |
| Amundi | 158.9k | 0.32% | $173.7M | added +22.7% | 2017 Q4 |
| Hsbc Holdings PLC | 158.9k | 0.32% | $173.6M | trimmed -20.8% | 2016 Q4 |
| Nuveen | 155.9k | 0.32% | $170.3M | trimmed -3.3% | 2016 Q3 |
| SEI Investments CO | 155.3k | 0.32% | $169.7M | trimmed -6.8% | ≤2013 |
| FIL LTD | 154.6k | 0.31% | $169.0M | trimmed -51.1% | 2024 Q3 |
| Dimensional Fund Advisors | 153.8k | 0.31% | $168.1M | added +1.8% | ≤2013 |
| Earnest Partners LLC | 151.8k | 0.31% | $165.9M | trimmed -3.1% | 2013 Q4 |
| Nomura Asset Management International INC. | 150.9k | 0.31% | $164.9M | trimmed -14.5% | 2023 Q4 |
| Artisan Partners | 150.9k | 0.31% | $164.9M | trimmed -1.9% | 2018 Q1 |
| Neuberger Berman Group LLC | 150.1k | 0.30% | $164.1M | trimmed -17.4% | 2013 Q4 |
| Nomura Asset Management CO LTD | 146.9k | 0.30% | $160.5M | added +25.5% | 2020 Q4 |
| Swiss National Bank | 140.5k | 0.28% | $153.6M | added +7.1% | ≤2013 |
Largest 50 of 1,080 shown; the full ranked, searchable register is at boothcheck.com/holders/MPWR. Related filers are grouped using the filings' own included-manager declarations. Historically, several managers opening new positions in the same quarter said almost nothing about the quarter that followed (59,118 cases since 2013). A filed record, not a forecast. Nothing here is investment advice.