Ticker · held by 3 filers

QSI

Quantum0Si Inc

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

Total value held

$18.9M

Total shares

17,515,552

Filers holding

3 · 5 positions

Caveat

long only · 13F-eligible managers only

Filers holding QSI

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

# Filer Class Shares Value (USD) % of port

1 ARK Invest · Cathie Wood Common Stock 7,021,571 $7.7M 0.05%

2 BlackRock · Larry Fink COM CL A 7,000,884 $7.4M 0.00%

3 Citadel Advisors · Ken Griffin COM CL A 2,676,097 $2.9M 0.00%

4 Citadel Advisors · Ken Griffin PUTCOM CL A 556,000 $611.6K 0.00%

5 Citadel Advisors · Ken Griffin CALLCOM CL A 261,000 $287.1K 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 QSI 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