They only trade asmall volume of shares every day based on the fund itself volume.

They are simple a reflection of the confidence in the upward or downward flow of investors into the fund and only a small % of the overall.... but when things turn positive they will also be a net buyer and move the stock price up regardless of what is on the ask maintaining there proportional position.

IE if investor intrest doubles the fund size, then the net positions in all the stock will double.

JMHO