My personal opinion is that the majority of the volume is institutions and not retail since most individuals are still shying away from the market and or they do not have discretionary funds to invest. As far as EVEP, the timing of your question is funny since last night it traded 700k after hours:
After Hours Most Active for Apr 11, 2012 : NOK, QQQ, KFT, CX, BAC, STD, HCA, EVEP, BIIB, MU, FAST, KLAC
EV Energy Partners, L.P. ( EVEP ) is -0.2 at $64.51, with 700,000 shares traded. As reported by Zacks, the current mean recommendation for EVEP is in the "buy range".