ION GEOPHYSICAL CORP

CUSIP: 462044108 Class: COM

RHUMBLINE ADVISERS's Holding History (CIK: 0001115418)

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

Q4 2015
Shares 207,244 Value ($000) $104 Avg Close — Range —
Q3 2015
Shares 220,074 Value ($000) $86 Avg Close — Range —
Q2 2015
Shares 210,606 Value ($000) $225 Avg Close — Range —
Q1 2015
Shares 205,631 Value ($000) $446 Avg Close — Range —
Q4 2014
Shares 194,431 Value ($000) $535 Avg Close — Range —
Q3 2014
Shares 184,431 Value ($000) $515 Avg Close — Range —
Q2 2014
Shares 184,431 Value ($000) $778 Avg Close — Range —
Q1 2014
Shares 188,549 Value ($000) $794 Avg Close — Range —
Q4 2013
Shares 198,739 Value ($000) $656 Avg Close — Range —
Q3 2013
Shares 215,689 Value ($000) $1,122 Avg Close — Range —
Q2 2013
Shares 218,144 Value ($000) $1,313 Avg Close — Range —