Volatility Indicators 
this indicator is from Jose Silva 

Volatility Stop 

R:=C/Mov(C,144,S); 
A:=Mov(C/Mov(C,144,S),21,S); 
UB1:=A*1.03; 
UB2:=A*1.06; 
LB1:=A*.97; 
LB2:=A*.94; 

UB1;UB2;LB1;LB2;R;
*****Volatility % W Brower *****
Lookback := Input("Time Periods",1,1000,50); 
HighVolatility := Input("High Volatility %",.01,100,3); 
100 * Sum(100 * ATR(1)/CLOSE > HighVolatility,Lookback)/Lookback
*****Volatility Natenberg *****
A:=Mov(Std(Log(C/Ref(C,-1)),10) * Sqrt(365),3,S); 
A;Ref(A,-1);
*****Volatility Trend*****
plots +1 for new high volatility for 20days and -1 for lowest Volatility for 20 days 

A:=Mov(Std(Log(C/Ref(C,-1)),10) * Sqrt(365),3,S); 
B:=If(A=HHV(A,20),1,If(A=LLV(A,20),-1,0)); 
B;
*****Volatility-adjusted, dynamic-period EMA v2.0 *****
{Volatility-adjusted, dynamic-period EMA v2.0} 
{©Copyright 2003 Jose Silva} 
{josesilva22@yahoo.com} 

pds:=Input("EMA periods",1,2520,21); 
x:=Input("use Open=1 High=2 Low=3 Close=4 Volume=5",1,5,4); 
plot:=Input("plot: EMA=1 volatility=2 dynamic EMA periods=3",1,3,1); 

x:=If(x=1,O,If(x=2,H,If(x=3,L,If(x=5,V,C)))); 
Vt:=Stdev(C,5)/Mov(Stdev(C,5),10,S); 
pds:=pds*.75/(Vt+.1); 
pds:=If(Cum(1)-13<pds,Cum(1)-13,pds); 
pds:=If(pds<1,1,pds); 
DyEma:=x*2/(pds+1)+PREV*(1-2/(pds+1)); 

If(plot=2,Vt*10,If(plot=3,pds,DyEma))