DOSSIER · 13F Holders · Q3 2026

SIMILARWEB LTD

3 institutions still hold SIMILARWEB LTD as of Q3 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP M84137904·3 13F holders·last filed Sep 30, 2026
Market cap
—
13F value held
$145K
visible holders
Holders
3
filers reporting
Concentration
60.96%
IMC-Chicago, LLC #1
top holder share
AI Holders Summary · Q3 2026

3 institutions reported SIMILARWEB LTD in Q3 2026. IMC-Chicago, LLC leads at 61.0% of the visible book.

Top holders

Sorted by position value. Source: SEC EDGAR 13F-HR filings.

#HolderValueShares% port.Quarter
01
IMC-Chicago, LLC
CIK 0001452861· Market maker
$88K11K0.00%Q3 2026
02
GROUP ONE TRADING LLC
CIK 0000932540
$57K7K0.00%Q3 2026
03
CONCOURSE FINANCIAL GROUP SECURITIES, INC.
CIK 0000752798
$00—Q2 2025