Thanks for all the responses on this thread; I had to do the day job today, so only just got back to this in the last hour or so.
It’s a shame tradex has ducked out, as in general his comments matched my confirmation bias, although with some caveats.
I can see that some market edges might disappear over time, as mentioned by
ValeryN, MrRenev,
ducatista and others, particularly things like arbitrage, or those based in some way on the mechanics of the market and regulations which might change over time. Also the early options traders seemed to have had more or less free money available to them as
zghorner mentions above. Also the more commonplace TA setups and indicators are probably of little use now as they have probably been flattened out by overuse. But I am still unconvinced that markets as a whole change that much in their behaviour, and that a robust system that works now, would not probably also have worked 50 years ago.
I get that volatility changes, and markets move from bearish to bullish, but I would hope a decent system would cope with that.
My own system, that has taken ages to develop as I started from zero knowledge 5 years or so ago, is very much a work in progress, but relies to some extent on repeating price action, but esoteric stuff that is nothing to do with traditional TA. For reasons some have gone into in this thread, I can’t really see how all the standard TA patterns and indicators can give an edge, unless they are combined in some way into a unique system. Otherwise surely they would be too predictable to work (for example, stops just below a fairly obvious ‘resistance’ level are surely going to often be hit by professional traders?). And the problem with combining lots of factors is that you may end up curve fitting a back test, and producing a system which only works in the past. Still having said that, I daresay there are people on hear using TA to make money.
“The markets are the same now as they were five to ten years ago because they keep changing - just like they did then” is a good quote. But I’m not sure it gets us much nearer an understanding of what changes apart from the things mentioned above.
tommcginnis and
Nobert – sorry, I couldn’t really see what you were getting at.
d08 – they were interesting comments, especially about the strategy that stopped working after 20 years. That sounds like something has happened to change things, but I suppose it’s hard to work out what.
Also a pity about the battle over trend following which seems to get onto loads of threads. I am not particularly a trend follower, but as a simple man, surely ultimately all systems make money from trend following of some sort, as the price has to move in your direction to make a profit? I must have got that wrong though…