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
Q4 2021Renaissance Technologies LLCBuy70,000202,300$10,388
Q3 2021ARK InvestSell-411,3072,619,323$174,447
Q3 2021Disciplined Growth InvestorsBuy211,2951,182,213$78,735
Q3 2021Mairs & Power Growth FundSell-60,482183,598$12,228
Q3 2021Renaissance Technologies LLCSell-29,083132,300$8,811
Q2 2021ARK InvestSell-624,2243,030,630$278,212
Q2 2021Disciplined Growth InvestorsBuy572,208970,918$89,130
Q2 2021Renaissance Technologies LLCBuy102,686161,383$14,815
Q2 2021Mairs & Power Growth FundBuy68,794244,080$22,407
Q1 2021ARK InvestSell-465,0683,654,854$444,978
Q1 2021Disciplined Growth InvestorsSell-222,767398,710$48,543
Q1 2021Renaissance Technologies LLCBuy49,39758,697$7,146
Q1 2021Mairs & Power Growth FundSell-25,224175,286$21,341
Q4 2020ARK InvestBuy1,025,8874,119,922$631,996
Q4 2020Disciplined Growth InvestorsSell-24,543621,477$95,335
Q4 2020Mairs & Power Growth FundSell-2,905200,510$30,758
Q3 2020ARK InvestBuy877,6293,094,035$400,678
Q3 2020Disciplined Growth InvestorsSell-18,754646,020$83,660
Q3 2020Mairs & Power Growth FundSell-10,548203,415$26,342
Q2 2020ARK InvestBuy613,7302,216,406$249,279
Q2 2020Disciplined Growth InvestorsSell-239,354664,774$74,767
Q2 2020Mairs & Power Growth FundSell-15,275213,963$24,064
Q1 2020ARK InvestBuy797,7511,602,676$122,012
Q1 2020Disciplined Growth InvestorsSell-16,146904,128$68,831
Q1 2020Mairs & Power Growth FundSell-1,331229,238$17,452
Q4 2019ARK InvestBuy124,887804,925$81,740
Q4 2019Disciplined Growth InvestorsBuy20,095920,274$93,454
Q4 2019Renaissance Technologies LLCSell-6,4009,300$944
Q4 2019Mairs & Power Growth FundSell-325230,569$23,414
Q3 2019ARK InvestBuy209,190680,038$69,432

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.

Related PRLB insights