MARKWEST ENERGY PARTNERS L P

CUSIP: 570759100 Class: UNIT LP PARTN

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

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

Q3 2015
Shares 23,549 Value ($000) $1,010 Avg Close — Range —
Q2 2015
Shares 8,408 Value ($000) $474 Avg Close — Range —
Q1 2015
Shares 32,984 Value ($000) $2,180 Avg Close — Range —
Q4 2014
Shares 50,154 Value ($000) $3,370 Avg Close — Range —
Q2 2014
Shares 14,415 Value ($000) $1,032 Avg Close — Range —
Q1 2014
Shares 19,733 Value ($000) $1,289 Avg Close — Range —
Q4 2013
Shares 7,249 Value ($000) $479 Avg Close — Range —
Q3 2013
Shares 36 Value ($000) $3 Avg Close — Range —
Q2 2013
Shares 7,508 Value ($000) $502 Avg Close — Range —