+100000000 Very difficult to do scalps anymore. The way "daytrading" is done now is to hold for much longer periods, gone are the days where a position held for 2 minutes was considered long. Personally I used to execute about 900-1200 trades a day, now.....5-10.
A lot of order execution algos in the wake of the financial crisis and the Obamanation have disappeared, especially in certain spaces where it was easy to read or even manipulate them based on L2. Will they be back? I hope so.
I personally don't think of trading as predicting anything. I developed my own methodology based on math / probabilities / statistics and the trades are not based on technical analysis. I KNOW that being able to DEFINE the RISK of the TRADE at ENTRY is an extremely valuable asset to the methodology. This is because ALL of my research shows that risking the same amount of capital per trade reduces drawdowns as well as smoothing out the PNL curve.