For hedging with an instrument that can be instantly liquidated without notice there are dual objectives: to minimise the variance of the hedged portfolio and the liquidation probability. Our optimal solution depends on characteristics of extreme returns and parameters that characterise the hedger. An empirical analysis of bitcoin yields an optimal strategy that combines superior hedge effectiveness with a greatly reduced probability of liquidation. We compare the performance of seven major direct and inverse hedging instruments traded on five different exchanges, based on minute-level data and link this performance to novel speculative trading metrics which differ markedly between exchanges.