PROTO LABS INC (PRLB) Institutional Ownership Changes & 13F Activity

PROTO LABS INC (PRLB) institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC 13F filings (Q1 2026). This page analyzes institutional buying and selling activity, new holdings, and sold-out positions among tracked filers. Notable filers include Disciplined Growth Investors, Polen Capital Management, Renaissance Technologies LLC, ARK Invest, and Mairs & Power Growth Fund.

Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q3 2019Renaissance Technologies LLCSell-33,10015,700$1,603
Q3 2019Disciplined Growth InvestorsBuy16,508900,179$91,908
Q3 2019Mairs & Power Growth FundSell-1,285230,894$23,574
Q2 2019ARK InvestBuy179,626470,848$54,628
Q2 2019Disciplined Growth InvestorsSell-36,392883,671$102,524
Q2 2019Mairs & Power Growth FundSell-997232,179$26,937
Q1 2019ARK InvestBuy213,256291,222$30,619
Q1 2019Mairs & Power Growth FundSell-33,403233,176$24,516
Q1 2019Renaissance Technologies LLCSell-23,30048,800$5,131
Q1 2019Disciplined Growth InvestorsSell-1,403920,063$96,735
Q4 2018Renaissance Technologies LLCBuy68,80072,100$8,132
Q4 2018Disciplined Growth InvestorsSell-17,669921,466$103,932
Q4 2018ARK InvestSell-2,87777,966$8,794
Q4 2018Mairs & Power Growth FundSell-676266,579$30,067
Q3 2018Mairs & Power Growth FundSell-39,518267,255$43,228
Q3 2018Disciplined Growth InvestorsBuy22,895939,135$151,905
Q3 2018ARK InvestBuy2,37480,843$13,076
Q2 2018ARK InvestSell-83,71278,469$9,334
Q2 2018Mairs & Power Growth FundSell-57,359306,773$36,491
Q2 2018Disciplined Growth InvestorsSell-9,910916,240$108,987
Q1 2018Disciplined Growth InvestorsSell-22,317926,150$108,869
Q1 2018Mairs & Power Growth FundSell-21,270364,132$42,804
Q1 2018ARK InvestSell-5,940162,181$19,064
Q4 2017Mairs & Power Growth FundSell-107,550385,402$39,696
Q4 2017ARK InvestSell-28,793168,121$17,316
Q4 2017Disciplined Growth InvestorsSell-2,298948,467$97,692
Q3 2017Mairs & Power Growth FundSell-15,325492,952$39,584
Q3 2017Disciplined Growth InvestorsSell-14,450950,765$76,346
Q3 2017ARK InvestSell-10,663196,914$15,812
Q2 2017Mairs & Power Growth FundBuy95,905508,277$34,182

Frequently asked questions about PRLB activity

  • Which institutional owners are buying PRLB?

    Institutional owners buying PRLB include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in PRLB activity?

    "Buy" means an investor increased their reported position in PRLB compared to the prior reporting period. This reflects growing exposure to PROTO LABS INC (PRLB) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in PRLB increasing?

    Institutional interest in PRLB can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.

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