Trendlines only work when you use them with other considerations and if they are properly drawn [scaled]
If the markets were static [which they aren't] then trendlines would work beautifully - the markets are dynamic and operate in cycles, how you define those cycles is up to each trader, put 10 of us in a room and we'll come up with 20+ cycle theories!
As the markets are dynamic, this is the REASON that sometimes things such as trend lines work and then they don't seem to - this will ALWAYS catch us out, always - you also need to move the TL's about the price chart [remember to keep the scaling EXACT]
Iconoclast1978 in the post above mentions we're in a simulation - He is absolutely spot on, the markets are mathematic, but also predictable - all you have to do is isolate the causes
This 1st chart shows the SP500 Index in LOG scale with trendline drawn from the 1982 low to 2000 high [PINK angle line], then simply copied to major LOWS - as you can see, it acted as a reference point for price during many major turbulent times
Here's a chart showing the DJIA - with trend lines coming into play and then out of action until years later! The market simulation theory can clearly be seen here!
If you accept that markets are not dong just 1 thing at a time, it becomes easier to understand/explain - multiple cycles are playing out - I accept that it is very very hard to crack this and this is the reason why it all seems illogical at times and as humans we work on fact, logical etc
To show you this, this next chart applies Fibonacci ratios to the 2009 LOW PRICE but we are now looking for this conversion to TIME:
This sequence has ended now)
Now I know I've not shown you trend lines as you would use them, Just wanted to show you what the markets are doing on the bigger scale
THT