You're doing the Yogi Berra restaurant thing, but with small caps?? "Nobody goes there anymore -- they're too popular." So, if a smallcap pops up biggly-huge, you want an exit triggered (or a trailing-stop tightened)??
Just so you know, you can solve the same problem using 'percentage change' rather than converting things into degrees. y=mx+b. Slope is rise over run. For one day, run is always 1. So 'rise' represents both the percentage increase and the angle of attack, essentially. So what? It only matters if speed (or simplicity) matters to you. I suspect "DEGREES(ATAN(LINEST(J4:J5)))" will take Excel longer to calculate than just the percentage change between price 1 and price 2. Never mind if this makes no sense to you.
%% That worked well in 2008; i'm not that bearish, now, but if you had to pick something to go down 50%, small caps could do it.
I'm using several parabolic indicators, percentage (or price multiple rather, parabolic price/previous price) is one of them. Angle is another. I'm also building some other indicators as well. I like the idea of angles because as a daytrader (and the daytraders that I know) what we intuively use to know when something is parabolic is that we glance at the chart and try to see if the price is going vertical. We try to get a sense of how steep is that rise, how close to 90° degrees the rise is. To me this is our intuition trying to figure the angle of that rise
%% That can work with stocks; but co... ETF'S like liquid SLV, can get killed on strong trend against you.
A little caution: Algebra will translate any dual (two points [x,y]) to any graph. But a chart relationship (as per, "90°") will be destroyed as soon as the context [x or y!] changes in the least. Careful!
%% Some use a % above 200day moving average; but like the money manager in WSJ that manages 77$ billion notes= ''a trend will go much more than you think''