spread betting 
noun [mass noun]
A form of betting in which the bettor wins or loses money according to the margin by which the value of a particular outcome varies from the spread of expected values quoted by the bookmaker.One of the attractions of spread betting is the ability to ‘go short’ - betting on a share going down....
- Although they are less risky than futures or spread betting where, potentially, your losses can be unlimited, they are certainly not suitable for beginners.
- The products that caused the most complaints were precipice bonds, spread betting, share tipping and those offering the facility to unlock a pension.