ION GEOPHYSICAL CORP

CUSIP: 462044108 Class: COM

AMERICAN CENTURY COMPANIES INC's Holding History (CIK: 0000748054)

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

Q1 2015
Shares 86,136 Value ($000) $187 Avg Close — Range —
Q4 2014
Shares 1,083,420 Value ($000) $2,979 Avg Close — Range —
Q3 2014
Shares 1,247,253 Value ($000) $3,480 Avg Close — Range —
Q2 2014
Shares 615,475 Value ($000) $2,597 Avg Close — Range —