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Copy and paste formula below.


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Trailing Stop - Elder's SafeZone
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{ Dr Alexander Elder's SafeZone trailing stop v2 }
{ Triggers: Long (+1) & Short (-1) signals at
  crossover of user-defined trailing stops }
{ ©Copyright 2003 Jose Silva }
{ http://www.metastocktools.com }

coefficient:=Input("SafeZone coefficient",
 0,10,2.5);
bkpds:=Input("Lookback periods",1,252,10);
pds:=Input("Trend EMA periods",2,252,21);
adv:=Input("plot:  today's SafeZone=0,  tomorrow's stop=1",0,1,0);
plot:=Input("plot:  trailing stop=1,  Long+Short=2,  signals=3",1,3,1);
delay:=Input("Entry and Exit signal delay",
 0,5,0);

DwSidePen:=Mov(C,pds,E)>Ref(Mov(C,pds,E),-1)
 AND L<Ref(L,-1);
DwSideDiff:=If(DwSidePen,Ref(L,-1)-L,0);
DwPenAvg:=Sum(DwSideDiff,bkpds)
 /(Sum(DwSidePen,bkpds)+.000001);
StLong:=Ref(L-DwPenAvg*coefficient,-1);
StopLong:=If(C<PREV,StLong,Max(StLong,PREV));

UpSidePen:=Mov(C,pds,E)<Ref(Mov(C,pds,E),-1)
 AND H>Ref(H,-1);
UpSideDiff:=If(UpSidePen,H-Ref(H,-1),0);
UpPenAvg:=Sum(UpSideDiff,bkpds)
 /(Sum(UpSidePen,bkpds)+.000001);
StShort:=Ref(H+UpPenAvg*coefficient,-1);
StopShort:=If(C>PREV,StShort,Min(StShort,PREV));

In:=Cross(C,Ref(StopShort,-1));
Out:=Cross(Ref(StopLong,-1),C);
flag:=BarsSince(Cum(In+Out>-1)=1 OR In)
 < BarsSince(Cum(In+Out>-1)=1 OR Out)
 +(Cum(In)=1);
signals:=Ref((Cum(In)=1
 AND Alert((Cum(In)=1)=0,2)
 OR flag AND Alert(flag=0,2))
  -(flag=0 AND Alert(flag,2)),-delay);

If(plot=1,Ref(If(flag=1,stopLong,stopShort),
 -1+adv),If(plot=2,Ref(stopLong,-1+adv),0));
If(plot=1,Ref(If(flag=1,stopLong,stopShort),
 -1+adv),If(plot=2,Ref(stopShort,-1+adv),
 signals))

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http://www.metastocktools.com