Further, together with wealth management investment funds, private equity funds, and of course investment banks and brokers, these institutions form the bulk of the market's "shorter-term players" - - organizations that are likely to have an investment horizon that is shorter than the typical person's. They're also more-likely to use aggressive investment techniques and invest in high-risk instruments.
Few deny that the above institutions, particularly hedge funds, with their buying power and volumes, have increased market liquidity.
However, lately a growing chorus is beginning to question the ultimate impact of hedge funds, and comparable players. Namely, they're asking if hedge funds and their companions are distorting prices of commodities, stocks, and other investments.

Marketwatch's Chuck Jaffe recently 

