DOSSIER · 13F Holders · Q2 2026

DATA I O CORP

3 institutions still hold DATA I O CORP as of Q2 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 237690902·3 13F holders·last filed Jun 30, 2026
Market cap
13F value held
$92K
visible holders
Holders
3
filers reporting
Concentration
58.37%
GROUP ONE TRADING LLC #1
top holder share
AI Holders Summary · Q2 2026

3 institutions reported DATA I O CORP in Q2 2026. GROUP ONE TRADING LLC leads at 58.4% of the visible book.

Top holders

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

#HolderValueShares% port.Quarter
01
GROUP ONE TRADING LLC
CIK 0000932540
$54K14K0.00%Q2 2026
02
SIMPLEX TRADING, LLC
CIK 0001488542
$38K10K0.00%Q2 2026
03
CONCOURSE FINANCIAL GROUP SECURITIES, INC.
CIK 0000752798
$00Q2 2025