Quote from Random.Capital:
Take out constant inflows from "retail", and the concept of sustainable alpha becomes pretty tenuous.
This.
The whole idea of large alpha in 2012 = "tenuous".
There has been a major Cultural Shift...
People get that retail trading = casino.
100% of my profits come from capturing $0.03-$0.04 spreads...
Whereas in the 90s there was lots of alpha.
Probably 90% of IB's profits come from market making operations...
And on down the list.
(But don't let reality stop you... flail for that "alpha").
Though get a large spike in volatility...
And the amount of alpha spikes concurrently...
So if you are not built to exploit Vol Spikes = you are toast.