MN, just so that you are not on the wrong track, and I am sure the others won't mind, they are NOT trend lines! Always have a target, but KNOW that it will not be hit all of the time. The better YOU get, the more times it WILL be hit TE
I wouldn't say you "need" them; they are just one of the things out there. You can also use narrow range bars, engulfing bars, pin bars, bars that form double tops, bars that form double bottoms, no bars, line charts, etc, etc, etc..............
Adequate Never let what others have, or have not, influence your way of thinking. Set your target when full time daytrading, starting with a realistic target of $300 - $500 per day, increasing as consistency is achieved, but never risking too much on a single trade. Normal days are for normal trading, while, exceptional days require exceptional trading. Your edge, as a daytrader, is just being there for when the exceptional days occur, and, those are the big pay days. TE
So those extra lines on TE's chart aren't trend lines so what could they be? How much importance do they have? Are they there to measure how steep the slope is and how much of a TIME expectation is for when the target will be hit?
I seldom look in here but come on, it's old hat and obvious. I've forgotten the name of the guy who came up with that idea but I can still remember the blue cover on his hardback. Was that 20 yrs back?