I can't call this a scam even if they are not sincere with what they say, so long as they are frequently issuing betting signals to you, they've delivered their own end of the bargain.

However, you need to know that gambling is risky, it's only a superbeing who can certainly promise you the prediction of an outcome that has not happened, and it happens as predicted. Are they superbeings? Certainly not! So, I advise you to think less of their hypes on the internet (if you see one). Even sports betting has a 50% chance, provided you are so good with your prediction.