If there would be a system that makes
consistently some 3% per month, then why shouldn't there be a system that makes 3% per day..? It's obviously the case that there will never be any such system. But if for some reason someone somewhen creates or created your desired system, then it would work
consistently only as long as no one knows about it. I mean as soon as such a system would become publicly available it would stop to work because everyone would try to use it and due to it's feedback on the price the market would most probably stall...
...stupid thoughts? maybe, but as reasonable as the system you are looking for.
Aleph
PS: From a certain point of view nothing in this world will ever be predictable. Maybe looking from
outside the universe everything allready happend, but if so, then it happend it every possible layout...

just my 2c