Quote from Cutten:
Well, from what you have been saying on this thread, you have been attacking trading strategies on the purely theoretical grounds of market efficiency. However, if you accept that markets are not perfectly efficient, then there is NO general theoretical argument whatsoever against any trading strategy at all. Therefore your entirely theory-based claims lose all their validity. You can't say "TA is BS because markets are efficient", then admit markets are not really efficient, and still stick to your claim based on your now-invalidated premise. This is the sort of naive undergrad logically fallacious economically illiterate BS that Malkiel has indulged in for his entire career.
A perfectly efficient market means that no trading strategy can make above average profits. A less than perfectly efficient market (even if it is still 99.99% efficienty) means that *any* strategy at all can, in theory, make superior profits. The assessment of any strategy at all, even financial astrology or dart-throwing, is then taken entirely out of the realm of theory, and becomes purely a matter of assessing the likely edge involved given real world-conditions, versus competition for that edge.
Therefore your entirely theoretical objections to simplistic TA such as trend-following become obsolete. There are no theoretical objections to TA in a less than perfectly efficient market. The only objections are practical - i.e. that the most knowledgeable, well capitalised, and efficient competitors are likely to discover and effectively implement any value-adding TA better than your average trader. But one can then bring in advantages to the smaller trader, such as focusing on secondary markets which are too small for instutitions to bother with, or looking at permanent institutional biases, such as having to cater to the naive biases and errors of their customers (think mutual funds having to sell at the bottom of financial panics due to investor withdrawals, even though the fund manager might be a raging bull). It now becomes a matter of empirical testing - theoretical arguments become nothing more than suggestions for where one might test most productively.