Casinos supporting Hong Kong Dollar Currency
Used primarily in the regions of Hong Kong and Macau, the Hong Kong dollar is the 13th most traded currency in the world due to those being such large international trading and tourism hubs.
Hong Kong was set up as a free trading port in 1841 and for many years used a combination of various currencies with no particular "official" one. This changed in 1845 when the British, who made it a policy to introduce sterling currency to all of its colonies, established the pound as the Hong Kong form of money and set its value at 4 shillings 2 pence to one Spanish or Mexican 8 reales coin.
This lasted for a while until the international silver crisis in 1873. Because there was such a fear of money losing all of its value, Hong Kong demanded that Britain produce a regular supply of silver coins to bolster the currency. This resulted in the introduction of British trade dollars, which eventually led to the adoption of the dollar as the official currency of the island in 1937.
Today a bank can only issue a Hong Kong dollar if they have an equivalent exchange of American Dollars on deposit. This keeps the currencies linked and makes it remarkably stable.