Call it the Huobi discount. Bitcoin’s move to $50,000 has revived bullish sentiment, lifting futures premiums on most major cryptocurrency exchanges. These premiums represent the difference between the price of bitcoin futures contracts traded on a given exchange and the broader spot-market price – often seen as a gauge of speculative interest. But on the Huobi exchange, historically skewed toward Chinese customers, the premium hasn’t budged. Analysts say the relatively low premium on Huobi might be the result of the exchange’s decision to suspend services to China-based clients. While the annualized three-month futures premium, or basis, has recently averaged around...