"Edge" is either (1) mathematical, or (2) a force in motion which you can get in front of... Discipline, if you think that's your edge, has neither quality. Not saying discipline isn't important... it's CRUCIAL... but it doesn't have the same expectancy as a genuine "edge".
Using what Bespoke said, let's define 'edge' as "repeatable with a positive expectancy." Semantics aside, and regardless of whether the newly defined 'edge' is illegal or legal, so far I can conclude that "finding an 'edge'" is tough. Or at least not as easy as a walk in the park. This is good news, because it means I'm not the odd one out. And it also means now I'm definitely NEVER giving up.
BTW---Discipline is an edge. So, is money management. Losing traders don't posses these two edges (sometimes).
The stop should be a function of information you have in the current market. If 'V' is the value of the stock at time t, then you have some expectation of V *conditioned* on the events that have transpired in the market prior to t. I can't dictate to you what information is useful or how to place a stop, other than to say setting a fixed stop is probably ignoring information that is useful. The debate shouldn't be between those two choices you've mentioned, the debate should be more around what information are you really ignoring. If you end up in a thought-circle like this, it's best to step back and question things rather than go in a loop. I'm a "loopy" thinker as well, but find it doesn't help me with trading.
Edge, imo, is a 'guaranteed' way to make money (positive expectancy, etc.). It says nothing of the volatility associated with capturing that edge or of the expected return. IMO, the RFR is an edge. Investing in a 5,10, 30yr treasury is an edge - it's just that there are more profitable edges that provide less volatile equity curves. Edge isn't as abstract as many people make it out to be. To that point, finding a poor edge is probably easier than finding a not poor one, but everyone has to start somewhere. I think everyone strives for an edge that provides tremendous return with zero volatility (not sure that legally exists in abundance), duh. M2c.
Delusions of edge... none of you have it... or you would be using it... not arguing over what it is, and what it is not... grow up fellas..
... or maybe some of us have them fully automated so we can spend the trading day browsing ET and having useless debates