Shorting a market that's recently undergone a significant price spike is actually a quite common strategy, betting that it's a temporary anomaly and will revert to the long-run trend. I have no idea whether it's a good strategy here, but it's hardly unusual. In fact, it's probably the common case: you short-sell things that you think are over-valued, and things that have undergone rapid escalations in price where your analysis doesn't conclude that the fundamentals support it are prime candidates. Lots of people made money shorting $140/barrel oil in 2008, for example; or shorting real-estate in the mid-2000s, which had been on a decade-long upward trajectory just prior to the crash.