ION GEOPHYSICAL CORP

CUSIP: 462044108 Class: COM

Walleye Trading LLC's Holding History (CIK: 0001388391)

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

Q4 2013
Shares 129 Value ($000) $0 Avg Close — Range —
Q3 2013
Shares 1,704 Value ($000) $9 Avg Close — Range —
Q2 2013
Shares 490 Value ($000) $3 Avg Close — Range —