I do believe they work (like in any other speculative market) but many traders tend to overcomplicate it. Too many lines on a chart are worse than no line.
I only use moving averages and classical chart analysis.
For example this MA worked pretty well (as support) throughout the whole 2016-2017 bitcoin bull run:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fi.imgur.com%2F7qH3G2D.png&t=663&c=UAgNqy2kiTB5nQ)
And maybe also during this one ....
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fi.imgur.com%2F0a4Nxn0.png&t=663&c=kW2t1m1A2f4sVw)
On a different timeframe as well:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fi.imgur.com%2FLljXPJW.png&t=663&c=LeQi2P16rBSICA)