DOCUMENT SEC SYS INC

CUSIP: 25614T309 Class: COM NEW

GROUP ONE TRADING, L.P.'s Holding History (CIK: 0000932540)

Note: Option positions (PUT/CALL) are excluded.

Q3 2021
Shares 4 Value ($000) $0 Avg Close — Range —
Q2 2021
Shares 4 Value ($000) $0 Avg Close — Range —
Q1 2021
Shares 4 Value ($000) $0 Avg Close — Range —
Q4 2020
Shares 4 Value ($000) $0 Avg Close — Range —
Q3 2020
Shares 8 Value ($000) $0 Avg Close — Range —
Q2 2020
Shares 521 Value ($000) $4 Avg Close — Range —