PROTO LABS INC (PRLB) Stock Institutional Trading Activity


PROTO LABS INC (PRLB) position changes reported by tracked institutional filers across multiple SEC 13F reporting periods. Based on recent SEC 13F filings (Q4 2025), investors with some of the largest reported share count changes include Disciplined Growth Investors, Renaissance Technologies LLC, Polen Capital Management, ARK Invest, and Mairs & Power Growth Fund. Explore insights into buying and selling patterns, position changes, and investment conviction levels to understand institutional trading behavior and market dynamics.

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Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q2 2023ARK InvestBuy1,127225,049$7,867,713
Q2 2023Renaissance Technologies LLCBuy51,416201,916$7,059
Q2 2023Disciplined Growth InvestorsSell-250,0091,746,115$61,044,180
Q1 2023ARK InvestSell-135,416223,922$7,423,014
Q1 2023Renaissance Technologies LLCBuy25,800150,500$4,989
Q1 2023Disciplined Growth InvestorsSell-125,7671,996,124$66,171,511
Q4 2022ARK InvestSell-203,740359,338$9,173,899
Q4 2022Renaissance Technologies LLCSell-13,700124,700$3,184
Q4 2022Mairs & Power Growth FundSell-55,26321,572$550,733
Q4 2022Disciplined Growth InvestorsBuy184,2782,121,891$54,171,877
Q3 2022ARK InvestSell-66,261563,078$20,513
Q3 2022Mairs & Power Growth FundSell-5,56876,835$2,799
Q3 2022Renaissance Technologies LLCBuy91,200138,400$5,042
Q3 2022Disciplined Growth InvestorsBuy60,6671,937,613$70,587
Q2 2022ARK InvestSell-35,006629,339$30,328
Q2 2022Renaissance Technologies LLCBuy43,30047,200$2,258
Q2 2022Mairs & Power Growth FundSell-8,79582,403$3,942
Q2 2022Disciplined Growth InvestorsBuy15,9701,876,946$89,793
Q1 2022ARK InvestSell-52,302664,345$35,144
Q1 2022Renaissance Technologies LLCSell-198,4003,900$206
Q1 2022Mairs & Power Growth FundSell-22,21391,198$4,824
Q1 2022Disciplined Growth InvestorsBuy69,0431,860,976$98,446
Q4 2021ARK InvestSell-1,902,676716,647$36,800
Q4 2021Mairs & Power Growth FundSell-70,187113,411$5,824
Q4 2021Renaissance Technologies LLCBuy70,000202,300$10,388
Q4 2021Disciplined Growth InvestorsBuy609,7201,791,933$92,016
Q3 2021ARK InvestSell-411,3072,619,323$174,447
Q3 2021Renaissance Technologies LLCSell-29,083132,300$8,811
Q3 2021Mairs & Power Growth FundSell-60,482183,598$12,228
Q3 2021Disciplined Growth InvestorsBuy211,2951,182,213$78,735

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.