ION GEOPHYSICAL CORP

CUSIP: 462044108 Class: COM

WELLINGTON MANAGEMENT GROUP LLP's Holding History (CIK: 0000902219)

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

Q3 2015
Shares 198,356 Value ($000) $78 Avg Close — Range —
Q2 2015
Shares 198,356 Value ($000) $212 Avg Close — Range —
Q1 2015
Shares 198,356 Value ($000) $430 Avg Close — Range —
Q4 2014
Shares 198,356 Value ($000) $546 Avg Close — Range —
Q3 2014
Shares 105,307 Value ($000) $294 Avg Close — Range —
Q2 2014
Shares 104,509 Value ($000) $441 Avg Close — Range —
Q1 2014
Shares 355,909 Value ($000) $1,498 Avg Close — Range —
Q4 2013
Shares 355,909 Value ($000) $1,175 Avg Close — Range —
Q3 2013
Shares 6,736,485 Value ($000) $35,029 Avg Close — Range —
Q2 2013
Shares 8,907,070 Value ($000) $53,620 Avg Close — Range —