That's right but now they are sucking everything they can out of their institutional clients trading back and forth.....
Wall Street decides a trend,takes a position and creates a move thru the use of leverage and fed money....convinces institutional clients that nows the time to invest (ala Goldman's recommendation today)and the institutions chase the trend allowing Wall Street to cash out.
That's why contraian trading works and long term investing (retail investor) doesn't
==>More like institutional and hedge funds were flying into these markets.
I'd guess it was more the likes of inhouse mutual funds buying the high fliers while the prop desk was selling to them. Who could possibly blame them for loading up on AAPL before the end of the quarter? LOL