A friend asked me why the ticker for gold is not called Gold, but XAU ？ It's like this, there is an international standard called ISO 4217. X represents the currency of non sovereign countries, and the chemical symbol for gold is Au So X+Au=XAU is gold. Similarly, silver is X+Ag, and platinum is X+Pt. On the other hand, the tick of a sovereign country's currency is the country code+name. USD=US (United States)+D (Dollar) Chinese Yuan=CN (China)+Y (Yuan) Japanese Yen JPY=JP (Japan)+Y (Yen) ---Dividing line--- In addition, in the early years, Bitmex and Bloomberg referred to BTC as XBT, which is also the reason for this. X=Non sovereign BT=BTC abbreviation, so we came up with an XBT. Otherwise, according to international standards, the first two BT country codes have already been assigned to Bhutan, so BTC may be Bhutanese Currency Bhutanese?? That is to say, when encountering Bhutan, which is a small country with little influence, BTC gradually regained its Ticker and did not become XBT. However, considering that Bhutan is also mining Bitcoin now, it is theoretically possible to see BTC-BTN trading pairs (Bitcoin Bhutanese Nu) in Bhutan 。