Some uninformed people would argue that spread betting in the UK refers to some kind of an unregulated futures market offered by the same bookmakers that provide sports betting and that spread betting providers are nothing more than bucket shops making up artificial prices.
This is far from the truth; spread betting being regulated by the Financial Conduct Authority that constantly scrutinizes spread trading providers and makes sure they operate in line with regulations. Market quotes are transparent and if you have Level 2 you will see that prices almost invariably mirror the market price. However, it is a fair point to say that spread betting may be unsuitable for long-term investing: buying and holding positions for years on end would turn out to be expensive. Having said that financial spread betting does have an advantage of no capital gains tax on profits.