ION GEOPHYSICAL CORP

CUSIP: 462044108 Class: COM

CALIFORNIA PUBLIC EMPLOYEES RETIREMENT SYSTEM's Holding History (CIK: 0000919079)

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

Q4 2015
Shares 601,900 Value ($000) $303 Avg Close — Range —
Q3 2015
Shares 498,400 Value ($000) $194 Avg Close — Range —
Q2 2015
Shares 558,300 Value ($000) $597 Avg Close — Range —
Q1 2015
Shares 558,300 Value ($000) $1,368 Avg Close — Range —
Q4 2014
Shares 558,300 Value ($000) $1,368 Avg Close — Range —
Q3 2014
Shares 504,100 Value ($000) $1,406 Avg Close — Range —
Q2 2014
Shares 483,900 Value ($000) $2,042 Avg Close — Range —
Q1 2014
Shares 483,900 Value ($000) $2,017 Avg Close — Range —
Q4 2013
Shares 399,600 Value ($000) $1,291 Avg Close — Range —
Q3 2013
Shares 287,767 Value ($000) $1,496 Avg Close — Range —
Q2 2013
Shares 241,167 Value ($000) $1,452 Avg Close — Range —