An edge in trading means positive statistical expectancy.
1 there are no sure things; but given combination of signals, sometime you have positive expectancy;
2. holding passive low cost etf gives you a sharpe about .3-.4, which is really a reward for taking on risks, ie risk premium; not an edge, but an upward bias for stock mkt;
3. many TA rules have slight edge, but when combined they are less than 1 sharpe;
4. there are many other biases, but none more than 1 sharpe.
Instead of finding ONE holy grail, spending time to accumulate a basket of small edges. 10 uncorrelated edges with 1 sharpe, can combine to have >3 Sharpe.
Just my 2c
