Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
251 institutional managers reported holding PRLB for the quarter ended Mar 31, 2026. Together they hold about 91% of shares outstanding; the top 10 hold 58%. 47 opened new positions; 27 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| BlackRock | 3.68M | 15.14% | $209.4M | added +1.6% | ≤2013 |
| Vanguard Group | 2.76M | 11.37% | $157.3M | added +3.6% | ≤2013 |
| Disciplined Growth Investors INC /MN | 2.50M | 10.28% | $142.2M | trimmed -6.6% | 2016 Q4 |
| Dimensional Fund Advisors | 1.27M | 5.24% | $72.5M | unchanged | ≤2013 |
| State Street | 1.09M | 4.50% | $62.2M | unchanged | ≤2013 |
| American Capital Management INC | 627.7k | 2.58% | $35.7M | trimmed -0.6% | 2025 Q1 |
| Geode Capital | 580.2k | 2.39% | $33.0M | added +3.9% | ≤2013 |
| Renaissance Technologies | 520.3k | 2.14% | $29.6M | added +5.4% | 2021 Q1 |
| Rubric Capital Management LP | 486.4k | 2.00% | $27.7M | trimmed -56.7% | 2025 Q1 |
| Arrowstreet Capital | 463.8k | 1.91% | $26.4M | added +0.7% | 2023 Q1 |
| FMR (Fidelity) | 422.4k | 1.74% | $24.1M | added +245.9% | 2017 Q2 |
| Prudential Financial INC | 400.2k | 1.65% | $22.8M | added +118.9% | 2015 Q2 |
| Driehaus Capital Management LLC | 369.1k | 1.52% | $21.0M | trimmed -3.4% | 2025 Q4 |
| Charles Schwab Investment Management | 360.2k | 1.48% | $20.5M | trimmed -0.8% | ≤2013 |
| Nuveen | 316.9k | 1.30% | $18.0M | trimmed -2.7% | 2019 Q2 |
| S Squared Technology, LLC (focused) | 296.1k | 1.22% | $16.9M | trimmed -3.3% | 2023 Q2 |
| Morgan Stanley | 293.6k | 1.21% | $16.7M | trimmed -3.9% | ≤2013 |
| Northern Trust | 267.0k | 1.10% | $15.2M | added +4.2% | ≤2013 |
| UBS | 234.5k | 0.96% | $13.4M | trimmed -2.3% | ≤2013 |
| D. E. Shaw | 225.7k | 0.93% | $12.8M | added +6% | 2018 Q1 |
| Nordea Investment Management AB | 214.4k | 0.88% | $12.2M | trimmed -4.5% | 2023 Q1 |
| Jupiter Asset Management LTD | 194.8k | 0.80% | $11.1M | unchanged | 2022 Q3 |
| Panagora Asset Management INC | 174.7k | 0.72% | $9.9M | trimmed -0.5% | 2022 Q2 |
| Hillsdale Investment Management INC. | 174.4k | 0.72% | $9.9M | added +3.6% | 2023 Q4 |
| Qube Research & Technologies LTD | 148.6k | 0.61% | $8.5M | added +894.1% | 2022 Q1 |
| Goldman Sachs | 140.9k | 0.58% | $8.0M | trimmed -12.2% | ≤2013 |
| BNY Mellon | 139.9k | 0.58% | $8.0M | trimmed -2.2% | ≤2013 |
| Principal Financial Group INC | 133.6k | 0.55% | $7.6M | trimmed -2.2% | ≤2013 |
| Bank OF America CORP /DE/ | 129.1k | 0.53% | $7.4M | added +38.3% | ≤2013 |
| Connor, Clark & Lunn Investment Management LTD. | 125.5k | 0.52% | $7.1M | trimmed -4% | 2021 Q3 |
| Rice Hall James & Associates, LLC | 113.6k | 0.47% | $6.5M | trimmed -0.9% | 2024 Q4 |
| Gagnon Securities LLC | 110.9k | 0.46% | $6.3M | trimmed -0.6% | 2019 Q1 |
| Public Sector Pension Investment Board | 105.6k | 0.43% | $6.0M | trimmed -4.3% | 2016 Q1 |
| Lazard Asset Management LLC | 99.3k | 0.41% | $5.7M | added +31.4% | 2024 Q3 |
| First Trust Advisors LP | 92.9k | 0.38% | $5.3M | trimmed -12.3% | 2017 Q2 |
| Invesco | 88.6k | 0.36% | $5.0M | trimmed -17.8% | 2016 Q1 |
| American Century Companies INC | 78.8k | 0.33% | $4.5M | unchanged | 2023 Q1 |
| Trexquant Investment LP | 68.7k | 0.28% | $3.9M | added +148.6% | 2023 Q3 |
| Marshall Wace | 68.4k | 0.28% | $3.9M | opened | 2026 Q1 |
| Informed Momentum CO LLC | 65.8k | 0.27% | $3.7M | opened | 2026 Q1 |
| Rhumbline Advisers | 65.1k | 0.27% | $3.7M | added +0.6% | ≤2013 |
| Polar Asset Management Partners INC. | 60.4k | 0.25% | $3.4M | trimmed -27.6% | 2025 Q3 |
| Ameriprise Financial INC | 58.5k | 0.24% | $3.3M | added +20.2% | ≤2013 |
| Legal & General Group PLC | 58.4k | 0.24% | $3.3M | trimmed -8.6% | 2014 Q3 |
| Jane Street | 57.4k | 0.24% | $3.3M | trimmed -48.1% | 2019 Q3 |
| Franklin Resources | 57.0k | 0.23% | $3.2M | added +72.9% | 2024 Q1 |
| AQR Capital | 55.1k | 0.23% | $3.1M | added +7.5% | 2020 Q3 |
| Hussman Strategic Advisors, INC. | 52.5k | 0.22% | $3.0M | opened | 2025 Q3 |
| Archon Capital Management LLC (focused) | 48.5k | 0.20% | $2.8M | opened | 2026 Q1 |
| Zacks Investment Management | 47.6k | 0.20% | $2.7M | added +641.7% | 2025 Q4 |
Largest 50 of 251 shown; the full ranked, searchable register is at boothcheck.com/holders/PRLB. 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.