They couldn’t have known

The thing very few people tell you about “overvalued” markets is that, occasionally, the fundamentals arrive to justify them. Later, of course, which is how risk takers are compensated for owning stocks selling at a higher than normal multiple. If there were no chance of this happening, then stocks would never reach these higher valuations to begin with, because no one would pay up for them. But it can happen....

source http://thereformedbroker.com/2018/06/27/they-couldnt-have-known-2/