THORATEC CORP

CUSIP: 885175307 Class: COM NEW

GROUP ONE TRADING, L.P.'s Holding History (CIK: 0000932540)

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

Q2 2015
Shares 20,896 Value ($000) $931 Avg Close — Range —
Q4 2014
Shares 2,390 Value ($000) $78 Avg Close — Range —
Q3 2014
Shares 4,884 Value ($000) $131 Avg Close — Range —
Q2 2014
Shares 4,185 Value ($000) $146 Avg Close — Range —
Q1 2014
Shares 2,731 Value ($000) $98 Avg Close — Range —
Q4 2013
Shares 6,331 Value ($000) $232 Avg Close — Range —
Q3 2013
Shares 245 Value ($000) $9 Avg Close — Range —
Q2 2013
Shares 621 Value ($000) $19 Avg Close — Range —