DAWSON GEOPHYSICAL CO

CUSIP: 239359102 Class: CMN

ALGERT GLOBAL LLC's Holding History (CIK: 0001275218)

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

Q4 2013
Shares 7,511 Value ($000) $254 Avg Close — Range —
Q3 2013
Shares 8,610 Value ($000) $280 Avg Close — Range —
Q2 2013
Shares 11,060 Value ($000) $408 Avg Close — Range —