ION GEOPHYSICAL CORP

CUSIP: 462044207 Class: COMMON STOCK

OBERWEIS ASSET MANAGEMENT INC/'s Holding History (CIK: 0000937886)

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

Q2 2018
Shares 38,925 Value ($000) $946 Avg Close — Range —
Q1 2018
Shares 30,225 Value ($000) $819 Avg Close — Range —