> That is, be on the cutting-edge of something, but be willing to bail out at the moment its future starts seeming questionable

Counterpoint, I sold all my Bitcoin in 2011 when Mt Gox got hacked and the price plummeted 80%. Would have done it again after their 2014 hack too if I had any left.

> Bitcoin is a good example: if you bought it 15 years ago and held it, you're probably quite wealthy by now

But you just said bail the moment it's future starts to be questionable. If you follow that you would have never held it for 15 years.