> How can you tell if a tech bubble is about to burst?

A bubble bursts when debt obligations exceed the ability to maintain that debt for multiple parties simultaneously, which results in a collapsing debt spiral.

It is challenging to tell when the collapse is close and even once it has started. Because it is challenging to predict the moment of burst the best course of action is to limit exposure by transferring the high risk obligations to someone else before everyone else rushes to do the same.