I thought it was 40% per month and I thought it was a scam because it is difficult for this offer to be real, but 40% per day is a scam without needing to think. It is difficult to find someone who can believe such a scam, but negative trust can be useful.
Well, there are always naive people or people who don't know about numbers that can fall into the trap. It is usually people with few resources who are blinded by a possible almost miraculous way out of their dire economic situation, so I was hesitating whether to create the flat after having left the first tag and I think it is right that the OP has created it to warn these potential victims.
But most likely scenario is that the scammer will not appear again on the forum, at least with that account. He has not logged in the forum since I left him the first tag.