MAST THERAPEUTICS INC

CUSIP: 576314108 Class: COM

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

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

Q2 2016
Shares 146,855 Value ($000) $69 Avg Close — Range —
Q1 2016
Shares 6,755 Value ($000) $2 Avg Close — Range —
Q4 2015
Shares 6,755 Value ($000) $3 Avg Close — Range —
Q3 2015
Shares 6,755 Value ($000) $4 Avg Close — Range —
Q2 2015
Shares 6,655 Value ($000) $3 Avg Close — Range —
Q1 2015
Shares 8,285 Value ($000) $4 Avg Close — Range —
Q4 2014
Shares 253 Value ($000) $0 Avg Close — Range —
Q3 2014
Shares 4,767 Value ($000) $3 Avg Close — Range —
Q4 2013
Shares 11,319 Value ($000) $5 Avg Close — Range —
Q3 2013
Shares 4 Value ($000) $0 Avg Close — Range —