[samlewis]

You can margin trade on exchanges like Poloniex right now. Whether or not it's a bright idea is another matter. Even if you assume that it's presently overvalued, how can you know when (or even if) the bubble will pop?

[gibybo]

Well that's always the risk with shorting I suppose, I just meant as safe as shorting can reasonably be :)

Thanks for the Poloniex tip though, looking into it now!