In an interview with the Wall Street Journal, the long-time associate of The Black Swan author Nassim Nicholas Taleb said a severe crash is on the way and stocks could lose more than half their value, while acknowledging that his latest warning should come as no surprise.

“I think we’re on the way to something really, really bad—but of course I’d say that,” Spitznagel said.

Since Fortune is mostly citing WSJ, here's an archive of that WSJ story. From that source:

Governments have been so active tamping down any conflagration in the economy that the dry brush of debt and other hidden risks have built into the ingredients for a severe blaze.

How should mere mortals without access to tail risk hedges respond to his prediction? Probably by doing nothing, says Spitznagel.

“Cassandras make terrible investors.”