Nice thread. So far I am only "working" on my edge and studying the market. But so far; chart reading and tape reading. I look for price/volume patterns and I am working on some setups where I combine these tools with risk and money management. - But thats the technical aspect of the game. The other aspect is mental and the keyword here is mindset.
Great question, especially since my company is Edge Trading, LLC. Without a doubt my Edge is technical analysis that focuses on trend following with a reversion strategy. I use Camarilla pivot points to determine the trend, then use a bunch of technical indicators to alert me to best entry prices. The rest of my Edge focuses on perfect money and risk management. I have created specific formulas that I follow to a T.
My edge is based on price action (price behavior at key levels, with "key" being defined by me based on many hours of study). This edge only dissolves if a liquid auction market were to dissolve. From the look of every historical chart I've seen and daily real-time trading for over 7 years, it's about as permanent as sunrise and sunset.