If the markets are weakly efficient, which methods would be useless to make extra profits?

If the market are weak efficient, then the technical analysis will be completely worthless because the technical analysis will mean that it will be trying to analyse the past prices and past information in order to derive the future prices but weak form of Efficient market will advocate that all the historical information and the past prices have already been discounted into the price and there is no scope for making any additional rate of return based upon those past prices and historical information which is the basis for the technical analysis and hence it can be said that technical analysis will be completely worthless.

TECHNICAL ANALYSIS is useless for making extra profits.