here's the link - https://www.bitmex.com/app/trade/XBTU17. On the chart is XBT futures (sept. 29) and a line of the XBT/USD cross. The futures must converge with the cross at expiration, right? So wouldn't it be a simple arbitrage to buy the lower one and sell the higher, then wait till expiration? (or close the trade when they cross earlier, of course.) you'd have to sit through some downside, but knowing you'd be profitable at the end. Does this work? Is this a normal financial futures trade? Forgive my noobieness, I've never traded futures, only options. It seems great.
Normally, futures and underlying converge. Do you have a contract specification from bitmex? What are the fees for shorting BTC? What is the interest rate they give you on USD holdings? What are the margin requirements for the future? What is the settlement, I assume physical?