Ticker · held by 4 filers

PRLB

PROTO LABS INC

All tracked filers currently holding PRLB, ranked by position size. Each row links through to the filer's full portfolio.

Total value held

$162.7M

Total shares

4,899,135

Filers holding

4 · 6 positions

Caveat

long only · 13F-eligible managers only

Filers holding PRLB

sorted by position size · click any filer to see their full portfolio

# Filer Class Shares Value (USD) % of port

1 BlackRock · Larry Fink COM 4,322,679 $133.5M 0.00%

2 Renaissance Technologies · Jim Simons (founder) COM 493,551 $25.0M 0.04%

3 ARK Invest · Cathie Wood Common Stock 56,744 $2.9M 0.02%

4 Citadel Advisors · Ken Griffin COM 12,461 $630.4K 0.00%

5 Citadel Advisors · Ken Griffin CALLCOM 6,900 $349.1K 0.00%

6 Citadel Advisors · Ken Griffin PUTCOM 6,800 $344.0K 0.00%

What this is

This page reverses the usual 13F view: instead of "what does Buffett hold," it answers "who holds NVDA?" Across the dozen tracked filers, all current 13F-disclosed holders of PRLB are listed, with the position size and what fraction of each filer's overall portfolio it represents.

Caveats: only the filers tracked here are included (~12 names) — not the whole 13F universe (~6,000 filers). Position values are at the most recent quarter-end, not current market price. Only long positions are visible; shorts and synthetics aren't.

v0.2 · 2026 · data via SEC EDGAR · CUSIP→ticker via OpenFIGI