I think Spread Betting is out of scope - as you mentioned it's regulated by the gambling authority, not the FCA. But as ever, lets see how it all works out.
Edit: It appears I was wrong, Spread Betting is in fact a CFD.
Date: 10 Jan 2018
The Financial Conduct Authority (FCA) said it “uncovered areas of serious concern” in the contracts for difference market, which is a type of betting on financial products banned in the US, but legal in the UK with a severe health warning. CFDs are a type of high-risk, complex derivative that allow investors to gamble on the price of an asset without owning it.
Shares in London-listed Plus500 fell by almost 5%, CMC Markets was down by nearly 4% in early trading and IG Group lost almost 5%. The intervention follows repeated warnings from European regulators about the risks posed by CFDs and a crackdown on the market.
In a letter to the industry after a year-long review, the City watchdog said it found...
... 76% of consumers had lost money on CFDs between July 2015 and June 2016