Chart - Potential Breakout Imminent, page-14

I'd say that TA is founded on the precise opposite of efficient markets.

I agree that if enough people base their trading off TA indicators this is reflected in historical pricing, which then makes historical prices predictive of future prices. This violates the weak form of the EMH which implies future prices are independent of all historical price data.

As our time scale increases, the predictiveness of past data becomes less and less relevant in predicting future prices. The best predictor is intrinsic value.