Matched betting, from my own research, is not classified as gambling because I understand that it is totally risk free and you cannot lose money while being guaranteed profit. Is it permissible?
If there was really no risk of loosing in "matched betting", you would have seen all wealthy companies investing in it. Matched betting is a type of calculated betting which means it is a type of gambling with small percentage of risk. It is a betting and betting is not allowed in Islam.
Wassalam.