If speculators are losing fortunes they are very bad in what they do. In most cases the well stacked speculators know how to avoid situations where they lose badly. If they aren't sure about the market, they tend to either go long or short with like 5-10% of their portfolio with a 10x leverage multiplier (percentages and multiplier are examples). The only thing most of the regular speculators care about is to make sure their dollar value doesn't end up getting beaten to the ground. BitMEX is the perfect platform for that considering that they can bet against the spot markets but settle in Bitcoin and get paid out in Bitcoin. No actual fiat is being used here.