From the documentation: EMPTY -1 Indicates empty state of the parameter. EMPTY_VALUE 0x7FFFFFFF Default custom indicator empty value. In other words, use EMPTY_VALUE for checking indicator result.
No, you're not supposed to get 60% positive results. If your strategy produces 100 trades, each trade losing 1 pip on average, and running on pair which have 2 pip spread, after reversing, the 100 trades will still see 1 pip loss on average, due to ...
Yeah, dont understand me wrong - I've been using MT4 since 2004, wrote well over 100 eas already, I think I know the platform pretty well.. yet it was the first time I've encountered this problem and it surprised me. Well, one learns all the time