I think that a very important difference between z5 and the others is that z5 was "backed by the Swiss National Bank" - as the documentation said.

In other words this was speculation based on facts of the outer (economic) world while z1-z3 do technical trading as I know.

The environment can change at any time but when nobody really knows why a strategy is working - I think this is mostly the case with the working strategies - then nobody can break the rule in a second.

So I think that Zorro developers made a mistake when they stated that z4 and z5 were safer.

And we also made a mistake because none of us found the problem. If you read the Zorro tutorial it should be very clear that a working strategy is not one which is "backed by the Swiss National Bank".

But a very important difference is that we have paid for z5 while the Zorro team made it for money and they said implicitly with the documentation (this is also true for z1-z3 in present): You only have to run it without knowing anything about the markets and the money will come. Trust me, I know what I am talking about.