> Irrational exuberance in stock performance.

And canals:

* https://en.wikipedia.org/wiki/Canal_Mania

And railroads:

* https://en.wikipedia.org/wiki/Railway_Mania

And a whole bunch of other things:

* https://en.wikipedia.org/wiki/Technological_Revolutions_and_...

Getting overly excited about things seems to just be a thin humans tend to do.