Guys and Gals, Keep it simple. An edge is any variable that you need (not what someone else needs or does not need) to be profitable because you see your losing results without the variable. Thus, an edge can be anything directly related to your trading or indirectly related to your trading.
Simple, perhaps. But it takes time and effort to test one's suppositions in order to determine whether or not they yield consistent profits over time. That is inescapable. One need only read these threads to arrive at that conclusion. Res ipsa loquitur.
I know this is going to scare off some of the older posters but cocaine has really helped me get a big edge in the markets. I read a book by Freud and decided to give it a try. I'm never tired, fully focused, and always thinking of new ideas. The only bad part is I have to have a bunch of kleenex around for my runny noses.
It's a known fact that some top athletes have used cocaine to enhance their performance prior to the start of mandatory drug testing in many professional sports. Used even though it has side effects (minor and serious...acute and chronic). Going further back into the past, cocaine has been used in many types of medical treatments until more suitable drugs were developed. Heck, it was even used in drinks like Coca-Cola for about 15 years (10 of those years documented) until the early 1900's. Anyways, I don't recommend the use of drugs except for medical purposes (e.g smoking marijuana for serious eye problems, severe obesity). Further, I think you can find other ways to help your lack of energy, lack of focus and thinking of ideas without the acute and chronic side effects that comes with cocaine use.
Scientific studies disagree with you although I'm sure you'll have extreme difficulties in finding a U.S. doctor to support such as a treatment. P.S. There's different causes of severe obesity.
OK let's cut through the BS. Edge is one thing and one thing only: positive expectation. If you have it, you can be a successful (aka long-term profitable) trader. Notice I said 'can', not 'will'. Edge alone isn't enough. You also need good money management, which is best exemplified as good position sizing. Without edge, all the best money management in the universe won't save your trading account. We see this easily in the simple examples of most casino games, where the house always has the edge (positive expectation) and the <s>suckers</s> gamblers are trying and failing to martingale, anti-martingale or otherwise enchant a path to success. Some get lucky in the short run, all fail in the long run. Here's why the OP fails to grasp the concept of edge. Say a trader does all the things in the first post (proper diet, proper exercise and rest, etc.) and as a result he comes across a strategy with permanent positive expectation. Great, all those things contributed to his success so he might think they were all part of his edge. Now he passes his strategy on to his son. Does the son now have an edge in the market? Of course he does. He has a trading strategy with permanent positive expectation. Did he have to go through the whole proper rest, etc. routine to get it? No he just needed to be a member of the Lucky Sperm club: he had a dad who was willing to give him dear old dad's successful trading plan. The kid has an edge but he didn't have to work for it like dad did. So clearly edge is something different from the process used to acquire it. Edge is the destination, not the journey. Yes most of us have to work for it to get it, but don't confuse processes with results.
A much cheaper, safer and very effective way to achieve the same effect is to do a short hard workout prior to trading, followed by some green tea and ginseng (I put the ginseng in a smoothie). Cocaine is a highly refined substance, and places you at for addiction, with psychosis and/or organ damage very likely down the road.
Yeah, this is the more common result of smoking marijuana: http://www.youtube.com/watch?v=rAOJJ15hHhk