Yes, it was me that introduced random as a definition of edge. Yes, getting long in a bull market is not random, but it is an edge. Many people congenitally just cannot do this.
Well, nearly. I think the very use of the words 'rally' and 'selloff' in your earlier post imply something about the markets that not all people would agree with. If you were an efficient market theorist (I am not one), then any move in the market is unpredictable, as all information is reflected in the current price. However, as soon as you talk about rallies and selloffs, you are implying that there is more than a 50% chance that price will continue moving in the same direction, and so you have a better than even chance of making money if you bet on the trend continuing. That to me is an edge and is what most people would call trend following I think. If you do not call that an edge, that’s fine, but if I don’t have somesuch edge in the long term, I don’t see how I could be profitable other than by chance. Regarding the random entry technique, mathematically I can’t see how that could work in the long run if the efficient market theory were correct. It would be like saying that money management could give you a winning system at roulette, which of course it can not. Perhaps if true, it is a proof of sorts that the efficient market theory is wrong. Unless you have a positive expectation when you make a bet, I don‘t see how any system can make money in the long term. I do remember reading about the random entry technique and in the example I saw it wasn’t tested on a huge amount of data. However, I suppose if trends are real (I think they are), it might be possible to devise a system that could take advantage of it with random entries.