It appears that I need to post more, so here you go.
By looking at a (lognormal) random walk, my eye can't tell if it's a real chart or a r.w. . Still what my eyes tell me is highly subjective. The real question is to what extent does the random walk theory exclude the existence of patterns,
Let's look at the basic Black-Scholes lognormal process,
dS/S = mu*dt+sigma*dW, (Eq 1)
where dW is the brownian component and mu is the deterministic component. Assume mu = mu(t) and sigma is a constant to make things easier.
The whole point in this formalism is not that there are no patterns in the stock chart. mu(t) can have patterns, it can even have momentum. None of this is conflicting (Eq 1). All the brownian component is adding is noise to that bit.
Now, from a hedging perspective, mu is replaced by the risk free rate and becomes irrelevant but a buy-side trader has absolutely no reason to do this, he's not interested in "killing" the brownian component of his options position in order to be hedged.
It makes perfect sense to look for patterns, the existence of a brownian component just makes his job harder as instead of a real pattern he may come up with something created by noise.
All the above is irrespective of whether the existing TA, as published by several authors in popular books is valid or not, but the results of trend following funds do hint that looking for patterns is a viable approach to trading.
Quote from atlTrader666:
I'm interested in the more esoteric technical analysis and why people believe it (against all evidence)... Aside support and resistance and some momentum patterns, the rest of TA seems like nonsense. Academics have tested TA strategies for half a century and they all call it bullsh1t. There is vague proof of short-term momentum. Only Benoit Mandelbrot discovered something valid: volatility tends to cluster. You can't make money of that though since traders have intuitively known and incorporate higher premiums in their options trading when volatility increases.
My question: If you were to create a random walk in Excel do you think you would differentiate the chart from say a stock market chart?
Seriously guys Google image a random walk chart or create one in Excel and you will be amazed at the amount of double tops/bottoms, bull/bear flags, breakouts from consolidation areas, etc. that you will discover. Even Fibonacci lines will look like viable entry & exit points.