Around 02:20 am on Tuesday, block 491,407 was mined on the Bitcoin blockchain, heralding the arrival of a new coin, Bitcoin Gold (BTG). A snapshot of current Bitcoin owners was taken and holders of the original coin at that time were awarded the new BTG coins on a 1:1 basis. Traders who were short of BTC at that time will be short of BTG on the same basis.
The new Bitcoin Gold network is not expected to go live until the start of November when the new coins will be credited, or taken away.
However, not all exchanges are expected to support Bitcoin Gold, including BitMex and Coinbase, although they may support the token at a later date. At the time of writing, the official Bitcoin Gold website, www.btcgpu.org, was out of service due to a DDoS attack due to over 10 million requests per minute.