It also is a pretty regular component of spread betting in all manner of ball sports esp football and cricket
CFD on the other hand is essentially a futures contract with the exception that neither party intends to take possession of the goods that the futures contract is derived from
CFD profits and losses are taxable/tax allowable, spread betting profits are tax free but losses are not allowable against other income.
This is how the tax man draws a line between defining a 'calculated' risk and a pure gamble.
Interesting. Thanks!