The BTC-U.S. dollar trading pair on Binance.US jumped as high as $28,800 earlier on Wednesday morning, some $1,700 higher than the average price across other exchanges at that time, data shows. Recently, the BTC-USD pair was changing hands at $27,900, while the CoinDesk Bitcoin Price Index (XBX), which feeds from prices on multiple exchanges, stood at around $26,400. The difference represents an almost 6% price premium on Binance.US.