ION GEOPHYSICAL CORP

CUSIP: 462044108 Class: COM

MASON STREET ADVISORS, LLC's Holding History (CIK: 0001167711)

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

Q3 2015
Shares 18,929 Value ($000) $7 Avg Close — Range —
Q2 2015
Shares 17,744 Value ($000) $19 Avg Close — Range —
Q1 2015
Shares 17,035 Value ($000) $37 Avg Close — Range —
Q4 2014
Shares 16,477 Value ($000) $45 Avg Close — Range —
Q3 2014
Shares 15,971 Value ($000) $45 Avg Close — Range —
Q2 2014
Shares 16,085 Value ($000) $68 Avg Close — Range —
Q1 2014
Shares 15,595 Value ($000) $66 Avg Close — Range —
Q4 2013
Shares 19,485 Value ($000) $64 Avg Close — Range —
Q3 2013
Shares 18,010 Value ($000) $94 Avg Close — Range —
Q2 2013
Shares 16,734 Value ($000) $101 Avg Close — Range —