I first saw this chart about 24 months ago and unfortunately couldn't find it again. Now I stumbled across it by chance and did a little research.

Importantly, this chart was first published in 1875.

I find the idea really interesting and am amazed that even the 2017 bull run is more or less visible. The first time I saw it, I thought to myself, cool, there could be a bull run in 2025/2026, and that's how it will be. Of course, I need to look into it a bit more because I think it will be important for the future. When to buy and when to sell.

How do you interpret this chart? Have you seen it before?